I just noticed the following error appearing once or twice per day over the last several days in my System Event log, Antivirus section:
Entry point GetProcessImageFileNameA not found in module D:\WINNT\system32\PSAPI.dll.
This only seems to have started happening since I installed build 4.5.531 - first occurrence was on 25-Nov-2004.
I'm running Windows 2000, SP4 + various hotfixes, in case that's significant.