it never closes on me while i'm working now that i've gotten a lappy with more power to handle my project. it's only if i leave maya idle and anything i didn't save won't be saved next time i open my scene up. i could be surfing the net and when i return it either closes at that time or it had closed already. sometimes i work on my project for a little while then i need to step away for a while to do something and when i get back maya is all closed down. the good thing though is that i've gotten into the habit most of the time to save my work before i step away. ususally when i forget to save i hadn't done alot.