Thanks. I put LimeWire on the old iMac because I was worried about system screwups after reading the warning comments about it. I keep the G4 10.3.6 machine free of any software I have any doubts about.
The problem fixed itself when I rebooted anyway. Now if I could only get the audio files to launch from the Library. As it is I need to go into the hard drive to System/Preferences/Shared folder and re-open them in Quicktime. A real bother to say the least. Just can't figure out what has happened. The first two audio files work fine, but all others since don't-they appear as a blank page icon with a title in the drive folder-but the video files I download are all hunky dory. Elmer Fudd is whispering in my ear about something scwewey going on around here.