Fast User Switching Problem

Archived from groups: microsoft.public.windowsxp.help_and_support (More info?)

What I have:
3 users, all administrators
Fast User Switching enabled

Here's the problem:
I can log on fine to account1, but when I switch user (winkey + L), and try
to log into account2/3 the screen freezes on the user's account picture
(doesn't get to loading settings). However if I click where my picture would
have been on the logon screen, account1 appears to log in (without the screen
unfreezing) and I can restart the PC with key presses (winkey, U, R)

I have tried:
Disabling Fast User Switching (logging out totally works fine)
the FSUFIX.reg fix (didn't seem to work)
replacing the termsrv.dll - file was in use so I couldn't replace

Any ideas?
JJK