I've definitely left it running for extended periods, so I need a little more information.
When it's locked up - is it the emulator that is locked up or the TI inside the emulator? For instance, do the menus still work?
Can you open the debugger, and leave it open to see if anything is printed when it hangs?
What is the TI side doing at the time that it hangs?
What's your host OS?