I think I may have noticed this once before, but now I know it's happening!
Just got back from a few days away and needed to check emails etc. Oh dear! ntl broadbean connection was down. As a double-check, I called up Start/Settings/Network Connections and my link status. The window popped up for about three seconds - then vanished. Tried calling it up again, it flashed very briefly on the screen and then disappeared - and that's all I can get without a full reboot, a brief flash! (Don't say it!)
I have also found that this is happening with the task manager.
Let's make this even more peculiar. I think this has only started since installing SP2.
The part about the network status window flashing immediately off was true. What I was thinking was the Task Manager isn't really. I SHOULD have said it's that window that pops up if you do the old 3-fingered salute of Ctrl+Alt+Delete.
I've run the usual of Adaware and Spybot.
I've just updated NAV and will give it a good full look through the system while I find out where I left the wine bottle before I went away.
Haven't got as far as the virus check yet, but I did double-check some of the 'freebies' that I have installed and remove them. I also downloaded HighjackThis and removed an iffy line (everything is still working) and that got the 3-fingered salute page back - which I now realise is called 'Windows Security'.