Are you sure its crashed, if it freezes it could be just that maya is calculating it and taking ages to do it, though saying that it should do it. I would probably give, strangly, ncloth a go, if you have it.

There is also "dynamica" that you can get form a thread over on CGtalk, I think the thread is "Disney Dynamics System" thats pretty good, nice and fast and you can have lots and lots of objects in there.

As for slowing down, I managed to mess maya up, not sure what I did, but it wouldent script anything, had to delete the preferences and it solved it.