Make a record of all your settings & then delete your LW preferences:
OS X: /Users/your_username/Library/Preferences/LimeWire
Windows: C:/Documents And Settings/your_username/.limewire
Linux: ~/.limewire

The folder is called .limewire & that's what you should delete.

Your connection could be poor b/c you're trying to dwnld too many files ot once OR you're force resuming too many files at once. The latter can have a major effect upon your connection quality. It's safer just to manually search for your sources. See this link (click on me) to learn more about that.

Also just to be on the safe side, do a connection test for incoming: See this sample for test (click on me.) And if your result is False post back here & tell us.