Render to uncompressed AVI, then use a third-party utility to convert to MPEG format. TMPG Encoder works well.

If you want DivX, install the DivX video codec, select AVI for output, and choose DivX for compression.

I normally use third-party utilities like VirtualDub to take uncompressed videos and encode them with DivX; they seem to turn out better that way, and I can do postwork on the video before compressing it.