My other thought would have been to delete the LW preferences folder whilst LW is closed. An internal error for LW 4.8, well that's odd.If deleting prefs doesn't work, then uninstall Java using the add/remove progs control panel. Then install Java 1.4.2 & see if it works then. If still no, then install 1.5 on top of that. But, install Java from your computer not over the net. Sometimes Java gets corrupted when installing over the net.
Fixes for Limewire