Unfortunately it's really hard to pinpoint totally random crashes like you guys are describing here.
The first thing to do would be to try to go through the steps in the first post here:
http://www.ootpdevelopments.com/boar...d.php?t=299986
Just to make sure things are totally up to date and that other programs are not running in the background that might trigger random crashes.
If it still happens, then as Matt mentioned, providing as much info as possible about exactly what is happening in-game just before the crash can help us out.