Edit ... missed you saying you had VISTA.
Things to try:
1. Try deleting your LW Preferences folder whilst LW is closed; instructions here: Point #2 & 3 in Fixes for Limewire (sample image included at bottom of page.)
If using VISTA then see http://www.gnutellaforums.com/genera...der-vista.html Make sure you make a note of important option settings before you remove your preferences settings! And after re-opening LW (not yet), make sure option to keep incompletes is larger than 7 days ... I choose 9999. And be sure save location is where old one was. But before you make those changes to LW settings, do step 2 below after deleting LW prefs folder.

2. (a) Remove all your Java versions (b) & download and install the OFFLINE installer version (online installations are commonly corrupted.) Download Java software from Sun Microsystems

3. After both of above, open up LW, go to Library window, select incomplete folder, select all the incomplete files and press the Resume button. That will force all back into Download window. Though they will show zero % initially, once started downloading will show previous downloaded %.