Hmm try a couple of things:
1. Try deleting your LW Preferences folder whilst LW is closed; instructions here: Fixes for Limewire
2. Whilst LW is open click on the Progress bar on the downld window. This will arrange all files by %. Then scroll down to the 1st at 0% & select it. Then scroll down to the last one at 0% & whilst holding SHIFT key select this one also. So with all those incompletes at 0% selected, click the Stop button. Then go to your incomplete folder (outside of LW), view it in list mode & by size. Then delete all those at 0 KB. This will reduce a lot of drag on LW when you open it.

Also when you open LW, let it settle for 10, 20 or 30 mins before using. And don't use the Resume/Find Sources button on all your files b/c this WILL cause side-FX such as slowing down your comp & LW, perhaps affecting LW's connection quality, & maybe even affecting your modem.