Rendering Issues

Hi guys, I have two rendering issues in 3DS Max. I have version 2010 and am rendering a scene which uses multiple lights, geometry, and also some FumeFX smoke.

My issues are these: when I render the sequence it will freeze at frame 168 (there are 860 total). I have tried this two ways. I have tried rendering a .mov file from start to finish and I have tried rendering .rpf files in 30-60 frame chunks. Both times it worked fine rendering each frame in around 3 minutes before freezing at 168.
Also, some of the frames have squares of un-rendered space once they finish. (You know how during the preview the small boxes traverse the frame and render bits at a time? Well, every so often it will skip a square which is left at the lower resolution pass, often resulting in a blurred and out of place square in the middle of the image.)

I have no idea how to fix these issues and was wondering if you guys knew? I am rendering at a large frame size, 1280x720, so that may be part of the issue. Another thing is that I THINK frame 168 is when the camera starts to move. Does that have any significance?

Let me know if you need any more information about the project, and thanks in advance!

Michael Schnyer
Aspiring Filmmaker and Editor
Canon XH-A1
After Effects
Premier Pro
3DS Max