Well the cross mount has holes in it, unthreaded (like it should be, just fyi). The two beams mounted to the board have the threads. The screws are supposed to go through the holes in the cross mount, and then threaded into to beams on the mobo.
Here is a crappy diagram of what the spring screws look like:
[===] -> screw head
> <
> < -> spring (it is around the screw)
> <
| |
| | -> part of screw unthreaded
\
/ -> part of screw threaded
\
The unthreaded part of the screw is too fat to fit through the holes in the cross mount. It should fit though. If it fits, the threaded part protrudes out the bottom, and is able to screw into the 2 board mounted beams. In my case, the unthreaded part is too fat, so the screw is not even protruding out the bottom of the cross mount holes.
I hope this helps describe a bit better.
Maybe time to break out the dremel...