What Java version have you been using? Some people have had problems with the latest Java update 1.6.0_02. If you've been using that version of Java without a problem, reinstall it. Use the JRE offline installer & remove your current Java version before installing this one.
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If that Java version's no good then try this older update. Same deal with deleting other Java versions before installing this one.
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Next, delete 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
This will kill all of your settings within options, so once LW's reinstalled you'll have to go back through afterwards & reset all of your options.

Last of all, reinstall LW & make sure to use the offline installer (when you click to download LW & the dialog box pops up, cancel that & use the option to download the offline installer).
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