Shoutbox

Does it do that too when you don't run msg plus (rightclick on the clock in systray, choose taskmanager > processestab...look for msgplus.exe, select it..rightclick > end task)!?

If not, do you have any plugins? If so disable all of em and see if the problem is still there (plus > preferences > plugins). Incase of more than one plugin: enable em one by one and see when the problem occurs.