Was tired after a busy day at work, and missed the sticky. Please follow the link.

http://milkyway.cs.rpi.edu/milkyway/forum_thread.php?id=3558

Same error for me. I have a 5870 and the same driver. The separation modified fit task are ok for me too but the Milkyway@home 1.2 say error when hit the 100%

- Unhandled Exception Record -
Reason: Access Violation (0xc0000005) at address 0x00007FFC5871C520 read attempt to address 0x00000010

Any idea?

This has been a long running issue. With 5xxx and 6xxx series cards you either have to remove milkyway from your preferences and run mod fit or use cat 12.8 or earlier. All the 13 and 14 drivers cause these cards to error here with a memory violation.