Ati2evxx.exe - Application Error

I get the following error at various times: When I exit Windows XP; At the
Windows XP logon screen; In Explore (Start Menu)

ATI video bios poller: Ati2evxx.exe - Application Error
The instruction at "0x7c911404" referenced memory at "0xfffffff8". The
memory could not be "red". Click OK to terminate the program Click on CANCEL
to debug the program

Clicking OK closes the error box, and also closes Explore (Start Menu) if I
get the message there. CANCEL does nothing.