Okay, I deleted the preferences, and downloaded the other version of the JRE and thought it was working fine, but 15 minutes later I got the same messege again: This program has performed an illegal operation. When that message box was closed another popped up telling me that Limewire still could not load the java runtime environment. I don't know why Limewire works for a while, and lets me get about halfway through some downloads, before it suddenly decides it doesn't work!