I just had something wierd happen...
I had a couple of 8057 work units folding on my 680's they were pretty much going to finish at the same time . One picked up a 7623 work unit

The 680 picked up a 8057 work unit. I walked away came back to check on things and found that the 8057 work unit had some kind of error and was punted and picked a 8018 work unit for replacement
05:30:42:WU00:FS00:Connecting to assign-GPU.stanford.edu:80
05:30:42:WU00:FS00:News: Welcome to [link=mailto:Folding@Home]Folding@Home[/link]
05:30:42:WU00:FS00:Assigned to work server 171.67.108.144
05:30:42:WU00:FS00:Requesting new work unit for slot 00: RUNNING gpu:0:"GF114 [GeForce GTX 680]" from 171.67.108.144
05:30:42:WU00:FS00:Connecting to 171.67.108.144:8080
05:30:42:WU00:FS00:Downloading 24.74KiB
05:30:42:WU00:FS00:Download complete
05:30:42:WU00:FS00:Received Unit: id:00 state:DOWNLOAD error:NO_ERROR project:8057 run:0 clone:148 gen:13 core:0x15 unit:0x000000146953ee30508b38a9cacd5cf1
05:32:24:WU01:FS00:0x15:Completed 50000000 out of 50000000 steps (100%).
05:32:24:WU01:FS00:0x15:Finished fah_main status=0
05:32:24:WU01:FS00:0x15:Successful run
05:32:24:WU01:FS00:0x15:DynamicWrapper: Finished Work Unit: sleep=10000
05:32:34:WU01:FS00:0x15:Reserved 326424 bytes for xtc file; Cosm status=0
05:32:34:WU01:FS00:0x15:Allocated 326424 bytes for xtc file
05:32:34:WU01:FS00:0x15:- Reading up to 326424 from "01/wudata_01.xtc": Read 326424
05:32:34:WU01:FS00:0x15:Read 326424 bytes from xtc file; available packet space=786104040
05:32:34:WU01:FS00:0x15:xtc file hash check passed.
05:32:34:WU01:FS00:0x15:Reserved 20400 20400 786104040 bytes for arc file=<01/wudata_01.trr> Cosm status=0
05:32:34:WU01:FS00:0x15:Allocated 20400 bytes for arc file
05:32:34:WU01:FS00:0x15:- Reading up to 20400 from "01/wudata_01.trr": Read 20400
05:32:34:WU01:FS00:0x15:Read 20400 bytes from arc file; available packet space=786083640
05:32:34:WU01:FS00:0x15:trr file hash check passed.
05:32:34:WU01:FS00:0x15:Allocated 544 bytes for edr file
05:32:34:WU01:FS00:0x15:Read bedfile
05:32:34:WU01:FS00:0x15:edr file hash check passed.
05:32:34:WU01:FS00:0x15:Allocated 36781 bytes for logfile
05:32:34:WU01:FS00:0x15:Read logfile
05:32:34:WU01:FS00:0x15:GuardedRun: success in DynamicWrapper
05:32:34:WU01:FS00:0x15:GuardedRun: done
05:32:34:WU01:FS00:0x15:Run: GuardedRun completed.
05:32:39:WU01:FS00:0x15:+ Opened results file
05:32:39:WU01:FS00:0x15:- Writing 384661 bytes of core data to disk...
05:32:39:WU01:FS00:0x15:Done: 384149 -> 352940 (compressed to 91.8 percent)
05:32:39:WU01:FS00:0x15: ... Done.
05:32:39:WU01:FS00:0x15:DeleteFrameFiles: successfully deleted file=01/wudata_01.ckp
05:32:39:WU01:FS00:0x15:Shutting down core
05:32:39:WU01:FS00:0x15:
05:32:39:WU01:FS00:0x15:Folding@home Core Shutdown: FINISHED_UNIT
05:32:39:WU01:FS00:FahCore returned: FINISHED_UNIT (100 = 0x64)
05:32:39:WU01:FS00:Sending unit results: id:01 state:SEND error:NO_ERROR project:8057 run:0 clone:309 gen:3 core:0x15 unit:0x000000036953ee30508b38b40deab612
05:32:39:WU01:FS00:Uploading 345.17KiB to 171.67.108.144
05:32:39:WU00:FS00:Starting
05:32:39:WU01:FS00:Connecting to 171.67.108.144:8080
05:32:39:WU00:FS00:Running FahCore: "C:\Program Files (x86)\FAHClient/FAHCoreWrapper.exe" C:/Users/Glens/AppData/Roaming/FAHClient/cores/www.stanford.edu/~pande/Win32/AMD64/NVIDIA/Fermi/beta/Core_15.fah/FahCore_15.exe -dir 00 -suffix 01 -version 702 -lifeline 5712 -checkpoint 15 -gpu 0
05:32:39:WU00:FS00:Started FahCore on PID 2332
05:32:39:WU00:FS00:Core PID:5456
05:32:39:WU00:FS00:FahCore 0x15 started
05:32:40:WU00:FS00:0x15:
05:32:40:WU00:FS00:0x15:*------------------------------*
05:32:40:WU00:FS00:0x15:Folding@Home GPU Core
05:32:40:WU00:FS00:0x15:Version 2.25 (Wed May 9 17:03:01 EDT 2012)
05:32:40:WU00:FS00:0x15:Build host AmoebaRemote
05:32:40:WU00:FS00:0x15:Board Type NVIDIA/CUDA
05:32:40:WU00:FS00:0x15:Core 15
05:32:40:WU00:FS00:0x15:
05:32:40:WU00:FS00:0x15:Window's signal control handler registered.
05:32:40:WU00:FS00:0x15:Preparing to commence simulation
05:32:40:WU00:FS00:0x15:- Looking at optimizations...
05:32:40:WU00:FS00:0x15:DeleteFrameFiles: successfully deleted file=00/wudata_01.ckp
05:32:40:WU00:FS00:0x15:- Created dyn
05:32:40:WU00:FS00:0x15:- Files status OK
05:32:40:WU00:FS00:0x15:sizeof(CORE_PACKET_HDR) = 512 file=<>
05:32:40:WU00:FS00:0x15:- Expanded 24820 -> 147034 (decompressed 592.4 percent)
05:32:40:WU00:FS00:0x15:Called DecompressByteArray: compressed_data_size=24820 data_size=147034, decompressed_data_size=147034 diff=0
05:32:40:WU00:FS00:0x15:- Digital signature verified
05:32:40:WU00:FS00:0x15:
05:32:40:WU00:FS00:0x15:Project: 8057 (Run 0, Clone 148, Gen 13)
05:32:40:WU00:FS00:0x15:
05:32:40:WU00:FS00:0x15:Assembly optimizations on if available.
05:32:40:WU00:FS00:0x15:Entering M.D.
05:32:42:WU00:FS00:0x15:Tpr hash 00/wudata_01.tpr: 1620551085 3558789170 1057902661 945192626 1823041927
05:32:42:WU00:FS00:0x15:GPU device id=0
05:32:42:WU00:FS00:0x15:mdrun_gpu returned -1
05:32:42:WU00:FS00:0x15:Going to send back what have done -- stepsTotalG=0
05:32:42:WU00:FS00:0x15:Work fraction=0.0000 steps=0.
05:32:42:WU01:FS00:Upload complete
05:32:42:WU01:FS00:Server responded WORK_ACK (400)
05:32:42:WU01:FS00:Final credit estimate, 17350.00 points
05:32:42:WU01:FS00:Cleaning up
05:32:46:WU00:FS00:0x15:logfile size=0 infoLength=0 edr=0 trr=25
05:32:46:WU00:FS00:0x15:+ Opened results file
05:32:46:WU00:FS00:0x15:- Writing 634 bytes of core data to disk...
05:32:46:WU00:FS00:0x15:Done: 122 -> 120 (compressed to 98.3 percent)
05:32:46:WU00:FS00:0x15: ... Done.
05:32:46:WU00:FS00:0x15:DeleteFrameFiles: successfully deleted file=00/wudata_01.ckp
05:32:46:WU00:FS00:0x15:
05:32:46:WU00:FS00:0x15:Folding@home Core Shutdown: UNSTABLE_MACHINE
05:32:46:WARNING:WU00:FS00:FahCore returned: UNSTABLE_MACHINE (122 = 0x7a)
05:32:46:WU00:FS00:Sending unit results: id:00 state:SEND error:FAULTY project:8057 run:0 clone:148 gen:13 core:0x15 unit:0x000000146953ee30508b38a9cacd5cf1
05:32:46:WU00:FS00:Uploading 632B to 171.67.108.144
05:32:46:WU00:FS00:Connecting to 171.67.108.144:8080
05:32:46:WU01:FS00:Connecting to assign-GPU.stanford.edu:80
05:32:46:WU00:FS00:Upload complete
05:32:46:WU00:FS00:Server responded WORK_ACK (400)
05:32:46:WU00:FS00:Cleaning up
05:32:47:WU01:FS00:News: Welcome to [link=mailto:Folding@Home]Folding@Home[/link]
05:32:47:WU01:FS00:Assigned to work server 171.67.108.142
05:32:47:WU01:FS00:Requesting new work unit for slot 00: READY gpu:0:"GF114 [GeForce GTX 680]" from 171.67.108.142
05:32:47:WU01:FS00:Connecting to 171.67.108.142:8080
05:32:47:WU01:FS00:Downloading 142.46KiB
05:32:47:WU01:FS00:Download complete
05:32:47:WU01:FS00:Received Unit: id:01 state:DOWNLOAD error:NO_ERROR project:8018 run:1182 clone:1 gen:7 core:0x15 unit:0x000000096953ee2e500f1f6921d215cc
05:32:48:WU01:FS00:Starting
05:32:48:WU01:FS00:Running FahCore: "C:\Program Files (x86)\FAHClient/FAHCoreWrapper.exe" C:/Users/Glens/AppData/Roaming/FAHClient/cores/www.stanford.edu/~pande/Win32/AMD64/NVIDIA/Fermi/beta/Core_15.fah/FahCore_15.exe -dir 01 -suffix 01 -version 702 -lifeline 5712 -checkpoint 15 -gpu 0
05:32:48:WU01:FS00:Started FahCore on PID 2188
05:32:48:WU01:FS00:Core PID:2268
05:32:48:WU01:FS00:FahCore 0x15 started
05:32:48:WU01:FS00:0x15:
05:32:48:WU01:FS00:0x15:*------------------------------*
05:32:48:WU01:FS00:0x15:Folding@Home GPU Core
05:32:48:WU01:FS00:0x15:Version 2.25 (Wed May 9 17:03:01 EDT 2012)
05:32:48:WU01:FS00:0x15:Build host AmoebaRemote
05:32:48:WU01:FS00:0x15:Board Type NVIDIA/CUDA
05:32:48:WU01:FS00:0x15:Core 15
05:32:48:WU01:FS00:0x15:
05:32:48:WU01:FS00:0x15:Window's signal control handler registered.
05:32:48:WU01:FS00:0x15:Preparing to commence simulation
05:32:48:WU01:FS00:0x15:- Looking at optimizations...
05:32:48:WU01:FS00:0x15:DeleteFrameFiles: successfully deleted file=01/wudata_01.ckp
05:32:48:WU01:FS00:0x15:- Created dyn
05:32:48:WU01:FS00:0x15:- Files status OK
05:32:48:WU01:FS00:0x15:sizeof(CORE_PACKET_HDR) = 512 file=<>
05:32:48:WU01:FS00:0x15:- Expanded 145371 -> 660986 (decompressed 454.6 percent)
05:32:48:WU01:FS00:0x15:Called DecompressByteArray: compressed_data_size=145371 data_size=660986, decompressed_data_size=660986 diff=0
05:32:48:WU01:FS00:0x15:- Digital signature verified
05:32:48:WU01:FS00:0x15:
05:32:48:WU01:FS00:0x15:Project: 8018 (Run 1182, Clone 1, Gen 7)
05:32:48:WU01:FS00:0x15:
05:32:48:WU01:FS00:0x15:Assembly optimizations on if available.
05:32:48:WU01:FS00:0x15:Entering M.D.
05:32:50:WU01:FS00:0x15:Tpr hash 01/wudata_01.tpr: 713512248 3970426948 3645068527 3688850908 2969401932
05:32:50:WU01:FS00:0x15:GPU device id=0
05:32:50:WU01:FS00:0x15:Working on GRowing Old MAkes el Chrono Sweat
05:32:50:WU01:FS00:0x15:Client config unavailable.
05:32:50:WU01:FS00:0x15:Starting GUI Server
05:32:57:WU02:FS01:0x15:Completed 1600000 out of 40000000 steps (4%).
05:33:58:WU01:FS00:0x15:Setting checkpoint frequency: 250000
05:33:58:WU01:FS00:0x15:Completed 3 out of 25000000 steps (0%).
05:37:43:WU01:FS00:0x15:Completed 250000 out of 25000000 steps (1%).
05:37:45:WU02:FS01:0x15:Completed 2000000 out of 40000000 steps (5%).
05:41:30:WU01:FS00:0x15:Completed 500000 out of 25000000 steps (2%).
05:42:33:WU02:FS01:0x15:Completed 2400000 out of 40000000 steps (6%).
05:45:16:WU01:FS00:0x15:Completed 750000 out of 25000000 steps (3%).
05:47:20:WU02:FS01:0x15:Completed 2800000 out of 40000000 steps (7%).
05:49:00:WU01:FS00:0x15:Completed 1000000 out of 25000000 steps (4%).
05:52:06:WU02:FS01:0x15:Completed 3200000 out of 40000000 steps (8%).
05:52:44:WU01:FS00:0x15:Completed 1250000 out of 25000000 steps (5%).