What's causing this window title bar weirdness?

[MoodyM]

Lately on my mid-2010 17" MBP (10.6.4) some of my window's title bars are exhibiting a graphical glitch that goes away if I move the window or move the focus, etc.

It happens in various apps (Finder, Firefox, etc)

Any ideas?

Screenshot here:

http://dl.dropbox.com/u/2213114/Weirdness.png

 

[Grannyville7989]

How perculiar.

What steps have you taken to try to correct this problem?