Just found a handy little <img src=/S/free.gif border=0 alt=free width=30 height=15> app that helps with this ongoing "feature" of the Windows O/S family:

Win-Res-Q 1.0 - Lost Window Rescue (read “win rescue”) is a simple utility that restores (shows) hidden windows. It can be used for bringing back your “lost” applications after their taskbar icons disappear following Explorer crashes that abundantly occur on Windows 98. It’s also useful for exposing strange, hidden windows lurking around your desktop.

Seems to work on XP too.