just a "stopped working" message, no other information? Have you tried rebooting the machine, sounds like you're running into a windows instability problem, when I start seeing behavior like this I usually reboot or start shutting down all the browsers windows I have running to free up some RAM. Sometime you'll see stopped working messages if you don't have enough RAM and the PC starts to thrash the disk swapping continuously with the RAM. (If your constraints are too complex that can increase the RAM usage.)
A reboot seems to be in order if it's not the amount of RAM in the system.
Regards