Are you sure you have not shared any files. If you go to the monitor window, you may only see current downloads taking place. Options/uploads/basic has a box to tick if you want to auto-clear completed uploads uncheck it.

Also go to Limewire's library and check if any shared files are showing hits, after about an hour of LW running most of them should show at least one hit. If they all show zero, you have a problem.

These are my even simpler questions