I've fixed the problem.
a process called windesktop.exe was running.
Of course without the task manager I couldn't see the processes running. I used a cool debugging software called PEBrowse Interactive and through it I managed to break and terminate this process.
Dialing up (ADSL is down) to post here seems to have put this bug back in the system.
I should get some good firewalling installed.
Good luck.