Always losing focus 3 seconds after I unlock Windows

[thinkpac]

My Windows XP is configured to always lock the screensaver after 15 minutes. A couple months ago I started noticing a problem where the active window would lose its focus 3 seconds after I unlock Windows. It happens every time I unlock Windows. It's annoying when I unlock Windows and I immediately start typing into the active application, but then 3 seconds later the application loses its focus and my typing results in a bunch of beeping, and I have to click on the application to give it the focus again.

It's weird that I didn't have this problem before, but it is now always happening. Not sure what happened to cause it.

[Majestic]

I would try uninstalling the video drivers and then reinstalling them. Possibly the video drivers got corrupted.