Ok - I have been going crazy on this one. But I now know that it isn't me. This has happened on several skins, so it is not a skin issue.
Window Blinds allows the skin developer to define the fonts used for several places in the interface. However, I have noticed that after time has passed, the desired font is being replaced by some other font in many areas of my interface. The most noticeably is the System Time on the task bar. I have taken 2 screen shots to show the good and the bad.
When I first apply a skin or when I reboot, this is what I see:

After some time the font changes to this:

See how it is now different - bold as well as a different font I think.
Re-applying the skin will force the font back to what it should be - at least temporarily.
Any ideas about what could be causing this? Or better yet, is this a bug in WindowBlinds that needs to be addressed? If you think I need to submit a bug report, let me know.
Einstein
OS: Windows XP sp3
WB version: 7.1 build 90 (x86)
Video: nVidia GeForce FX 5200