Jon,
I have found a bug with DF title bar buttons and PSPad (http://forum.pspad.com/list.php?6) v4.5.5 (238x). This has been apparent for several versions of DF betas and several versions of PSPad.
Steps to repro:
1) PSPad is on second monitor with DF taskbar.
2) Minimize PSPad to DF taskbar
3) Restore PSPad to second monitor.
Ghost Title Bar buttons appear on monitor 1. Clicking these buttons make them disappear. Title Bar buttons always visable on PSPad.
W4 Enterprise x64 nVidia Quadro.

Jon,
Just so you know it seems to have fixed it on all my machines I tested it on.
Pete