keyboard layout differing on login

I don't know if this has been commented already as I don't find a specific reference about following problem.
I have four virtual machine installed under Parallels 5. Windows 2000 Professionnel, Windows XP Professionnel SP3, Windows 7 beta and Ubuntu 9.10.
I use a MacBook Pro with Azerty keyboard and a US version of Parallels.
With Windows XP I use the French Swiss keyboard. For all four machines the Azerty keyboard is quite well recognized. Except that, for Windows 2000 and Windows XP, only on login the "!" is replaced by "=". So password containing this "!" character have to be typed as ......=...
Once logged in, everything is OK.
This problem doesn't appear at all under Windows 7 or Ubuntu.
BTW it is not the only character which differs from the real azerty keyboard layout: @ is replaced by upper 2, ! by - and - by = (there are probably a few more...)
It is only a minor annoyance. It existed already under Parallels 4.