Actually, it was the Library window that made me understand that something really wrong had happened. I originally clicked on the alias for the Shared folder that I keep in my Dock and got nothing but a big, gray question mark.

I then opened LimeWire and checked the Library and only saw an "Incomplete" folder - no more "Shared" folder.

I've tried everything I can think of to find some remnant of one of the files it contained that I could try to trace, but nothing showed up.