I know it doesn't help, but Rocktron and I both had similar problems. They started last Thursday.
I had serious problems with a WU from project 524,
locked up the machine 3 times in a row, every time restarting at 0/500 :angry:
Deleting the work-folder doesn't help as the F@H servers just hand out the same WU over and over again.
As a temp solution I made a backup of my WU several times a day using WinZip.
Shutdown F@H first before zipping it, as F@H writes "shutdown in a normal way" to disk.
Failure to do so (as in a lockup) will restart your WU @ 0/500 when you use the backed up files.
Now what is the cause?
The only thing I can think of:
I used a proggy "CWShredder" mentioned here on the forum. Could it be we all used the same proggy? 
