What does the crash report say? What stuff is used in the project? we need more info.
Here's a shot in the dark: if you're using Open GL to accelerate your renders, don't. Turn it off and leave it off. Adobe employees don't use Open GL when they render, and you shouldn't either. Since Adobe employees frequent this forum, you'll know soon enough if I'm fibbing.
Memory settings in AE are complete Voodoo... Properly configuring your RAM etc within after effects is a mindbender and very counter intuitve.
You've probably already read over this link, but just in case...
I find that even when my settings are good, i get a hang or a failed render if I don't purge the ram etc before I start a render.