::suggestion::
run your anit-virus prog to check for viruses.....though at this time I don't think it is...your sys resources could be overused which means when information is being transferred from your hdd to ram and back ...something like that the information can be mutated either through a ram bug or because your computer can't handle it due to numerous progs running simultaneously.
it happened to me in word97 but I wasn't running anything else except nav, configsafe and the little sound thingy on the nav bar next to time..I was copying huge amount of data among two word files and word crashed...the bad thing was I couldn't open either files anymore...I had been working on it for 3 months, but only made a backup at 2 months....so I lost a months worth of summarised origin data for my fs2 project. wah wah wah
well hope this helps
