It "might" be related to graphic card issues such as these (even if you don't suffer the same side-fx): 1. The way to fix the Blank screen on startup, & also 2. GeoForce 3D setting, & also 3. Fix for LW interface blank spots problem

It might be worth checking out the LW beta 4.12: http://www.limewire.com/english/content/beta.shtml

Have you checked the Limewire folder for any log files? I just recently began having this problem as well. At times, Limewire would shut down and then freeze my computer! I found some intesting stuff in them. They're worth a look (my problem is somewhere in Limewire.jar where a EXCEPTION_FLT_DIVIDE_BY_ZERO error is created. I have half a mind to personally decompile the jar and try to fix the error).
Yeah well, anyways, if Limewire has crashed, you might be able to find some log files.

Good luck...