It have allways annoyed me to have those ghosted taskbars in win98 when some screensavers (typically opengl ones) or programs exit. Finally I found something to fix it.
The link below describe how to Remove 3 fixes by Microsoft, that conflicts with the original user.exe and user32.dll. But you better read it yourself, since I'm no window expert.
http://www.generation.net/~hleboeuf/tas ... m#TASKBAR5
Best regards