Thanks a lot!
For those who were confused about my rather cryptic question:
When Windows XP sees that you have three or four windows open with the same application, in my case IE 6, it groups all of the icons corresponding to each window into one icon These icons would normally be three or four across the taskbar, and are merged into one icon with the ability to "open up" vertically so you can select a window from the group.
I don't know, it could be a good feature, but right now I'm so used to having an icon for each application in the taskbar.
Mark