Try 2 things:

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.)

2. Tip: Purge the Downloads Queue! (click on blue link). Which can really refreshen LW's performance.

If still no good then:

3. Remove all versions of Java & downgrade to Java 1.5_10 Archive: Download Java 2 Platform Standard Edition (J2SE) 5.0 Update 10

I've tried to delete that folder .limewire(lw preferences) while LW is closed and actually tried when I removed it from my PC.. it will not delete.

I have no incomplete files.