I seem to have figured out how to stop it crashing (at least, in my game).  Turn off the Memory Notifications.  I've been playing a game that used to ctd every five minutes for about two hours crash-free now.  I could be wrong, there might just be a crash lying in wait to ambush me when I least expect it, but so far so good.

Also FullfillWantsWithoutLocking doesn't allow unlocked wants to give you points; it gives you the moodlet and you see the floating numbers, but no points have actually been added.  Might just be me, but I thought I should mention it while I'm over here.