conswan, I would request the MOD's to move this to the bridge forum.
In the mean time you can try opening Bridge while pressing
Alt + Ctrl + Shift Key on Windows
Cmd + Shift + Ctrl on MAC
That will reset the preferences for Bridge.
We would also suggest you to have a look at this thread.
Moving this discussion to the Bridge General Discussion forum.
More detail. OS? Previous verions? What does it do? Make sure CS5 is not running in background.