Which version of Java do you have installed?

Try either installing the latest version of Java or rolling back to an earlier version. Download the JRE offline installer & remove any other Java versions installed (via Control Panel) before you install another version.

Latest Java: Java SE Downloads - Sun Developer Network (SDN)

Earlier Java (JRE 6u5): Archive: Download Java Platform Standard Edition (Java SE) 6u5

If that doesn't help, try deleting LW's preferences folder when LW's properly closed. See point 3 here & also point 2 if you've used older versions of LW in the past (there could be a folder in either location).
Fixes for LimeWire
LimeWire Pref Folder in Vista
This will change all of your settings within LW's options. Providing LW stays open, you'll have to go back through tools > options afterwards & reset things to your own preferences.

If none of those things help, maybe it's a bug in the new version. You can report bugs or any issues with LW 5 over at this other forum (click on link): LimeWire Forums

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