About 50% of the time, when I wake my computer up out of sleep, I am unable to change the foreground window. If I press command-tab, nothing happens. If I click on another icon in the taskbar, then it doesn't come to the front nor does the name change in the top-left corner (the currently focussed app).
Here are my specs:
OS X 10.6.3
Macbook Pro
Usually open applications:
Chrome
Adium
Colloquy
Mail
iCal
TextMate
If I put it back into a screensaver (or sleep) then when I put in my password again, it usually will fix the problem.