First, LimeWire has a chat feature. You (by default) have it enabled. Someone was trying to contact you via this feature. It is nothing to worry about. If you don't want it, go into Tools->Options->Chat and disable it.

Second, after uninstalling LimeWire, did you make sure the .limewire file was deleted?
I think it might stay in your directory. On XP it is in C:\Documents and Settings\(your profile)\.limewire
As mentioned it will remove your preferences, but those can be set up again after you reinstall LimeWire. This was the suggestion mentioned above and it worked for me. You could also try the beta version 2.9.9.

Third, as long as you don't delete the location your songs are stored....
ex. C:\Program Files\LimeWired\Shared
...your music should remain intact. Uninstalling LimeWire does not delete this directory.
If you are still worried, copy them to another directory. Good Luck!