Blender Crashes in Cycles Animation Render Several Frames In

Hello all, I recently switched from blender internal to cycles for rendering my animations. Still frame renders work fine but whenever I go to render an entire animation, a few frames in blender crashes and gives me “this program is not responding”. Any ideas?
Running on:
Windows 7
i7 3770
12 gb Ram
Nvidea GeForce Gtx 660