USB removable momory issue

In the past I have used my jumpdrive to move songs from computer A to computer B. However recently seemingly at random nine songs copy themselves to my jumpdrive. It isn't really a serious problem, but it really has me curious. I have defragmented the jumpdrive and I thought I had deleted all traces of the songs. Could it be in the way I have wmp configured? Any other ideas? Thanks in advance!!!!!!!! Windows XP Media Center 2005 WMP v.10

its probably reading that from a previous cached paged. What type of file(s) were they… like Mp3 …etc

the files were all .wma I believe, I can't say for certain. Would it matter if there were also .mp3 files? (that would be the only other possible file type I could think of.) Does it matter if I leave my USB drive in when I shut down my computer? On my previous computer, it required me to remove the thing before I shut down so the computer wouldn't try to run anything on the USB disk while booting (or something to that effect).

A friend has said there may be a problem in the "table of contents" in my jump drive. Is this accessable via the properties menu?