Which version of Java did you change to...the latest update, or the older version 1.5.0_11? Whichever one you used, try the other one. Remember to remove any other Java versions on your computer before installing another version.

Uninstall LW again, using the uninstaller associated with LW. Then use your computer's search to look for all files & folders with limewire in the name & delete those. Reinstall LW & remember to use the offline installer (that was mentioned in the thread you originally looked at).

Did you have any problems with finding LW's preferences folder (in order to delete it)?

Edit: Problem solved by deleting the preferences folder!