Maybe a silly question but one day I did something accidentally in VS2008 and ever since then, whenever I hit F5, just before my app appears, I see a quick flash of a small window labeled "Object Test Bench". ie, it appears and very quickly disappears.
I've read about Object Test Bench and (since this happened) had a quick play with it in View / Other Windows but I haven't been able to stop that quick flash.
It's not really a problem, VS seems to work fine but I'm always uncomfortable about something happening that I don't understand and didn't happen before.