Hmm.. I just d/led limewire 4.12.3 from download.com/cnet.
1.5.0_06-b05 is my Java build.
I scan every 3 or so days with spybot, adaware, and AVG - everything's clean.
I defrag every week or two, last time was 2 days ago.

This is very, very strange. I'm definately knowlegeable with computers and rarely run into an issue I can't figure out by doing a little research... but this one has me totally stumped. I'm wondering if some of the extra Windows services I disabled could have anything to do with this, but I don't see which one(s) would be required for limewire to run.