Microsoft suggest that this error message is caused by a DLL loading with the same base address as USER but before USER is loaded. There are a couple of causes, one on XP SP2 (documented
here[
^]with a fix), the other being that someone tried to rebase a DLL to the same base address as USER.
As it's your own code I doubt it's the second, but you may be using a third party DLL that's causing the conflict.
Cheers,
Ash