vidding_livejournal_ark2 | 2 questions: exporting from InterVideo Creator, and ripping for DVD-quality vid

I have a couple of questions relating to making/exporting DVD-quality vids, which are quite different in nature, and it may well be that I just suck and don't understand things that have v. simple answers, but I'll throw them out here and help would be very much appreciated. :)

Question 1: Program crashing with 200MB+ exports
I use InterVideo WinDVD Creator 2. I'm trying to export a 4-minute vid as 720x480 NTSC MPEG-2 at 6500kpbs (the codec is just InterVideo MPEG, I think), which should have an end product of about 220MB, but the program always encounters a runtime error at about the 95% mark and shuts down, leaving a partially completed vid file of ~200MB and a truncated ending.

I tried cutting the vid down to 3 minutes, and that worked fine with an output file of ~160MB. So I'm pretty sure it's the size of the file that's screwing me over - it looks like 200MB is like a sort of "critical mass", and the program/my computer just can't handle more exporting beyond that. Which means I can do this for vids that are about 3:30 minutes or less, but not any longer. I would reduce the bitrate (I think the vid would actually run smoother if I went down to about 5300kbps), except all my export parameters are preset and I can't actually alter them.

My OS is WinXP, processor is AMD Athlon XP ~1.2GHz, 256MB RAM, my virtual memory paging file is increased to the absolute maximum, I shut down all background processes, and I have about 10GB free on a 80GB hard drive. Is there anything I could do to stop the rat bastard program from screwing up when it hits the 200MB mark?

Question 2: Ripping clips for DVD quality video
If I export my vids at decent DVD quality (720x480 NTSC MPEG-2, 6500kpbs), what bitrate should I be setting when I'm ripping the source clips from DVD? More than 6500kbps? I use ImToo DVD Ripper and encode my source footage in DivX AVI.

Many thanks!