FIXED ! Was an ESX version issue (VMware) Klaus Karby 12.Sep.08 08:34 AM a Web browser Sametime Entry 8.0.1Windows
After hours of reconfiguring and troubleshooting in Domino I found out the server was moved last night from VMware ESX 3.5 test environment into VMware ESX 3.2 production environment. The operation should be a no brainer, (same server, same session, same IP, same DNS etc.) and VMware guys refused this had anything to do with the "bouncing users" issue. But I argued since there was a difference in ESX version there might be issues i.e. with network. I made them move the virtual server back into the ESX 3.5 test environtment and all works now.
So the morale must be : make sure ESX test and production environemts are same versions.