VNC key strokes issue

We are facing a strange and very annoying issue with OpenSuse 11.1, configured with Xvnc servers running for each user.
When connecting to our desktop with a VNC client (3 different tested), the shifted characters are repeated. For example, if i want to do a single ‘1’, it begins to output 1, then a bunch of ‘!’ and then some ‘1’ again until i break it with CTRL-C. It happens with all shifted characters (Note that we are using a french keyboard - AZERTY - , so 1 is obtained with SHIFT+1).
Same issue with characters obtained with ALT-GR.
After additionnal tests, we discover also that the issue is present with KDE, IceWM, but not TWM (?).

Any idea, patch or fix in the pipe ?

Nobody is facing the same issue ???