iPhone and MP4 files?

I just picked up an iPhone, and once I got it working with my wireless router, attempted to view an MP4 video file on it. It will load, and begin to play, but after a few seconds the phone resets itself. This has happened numerous times, it's a fairly large file -- 65 megs -- but plays fine on my MacPro.

Is there some limit to the size of an MP4 file the iPhone can handle or do I have some other problem with my particular phone? I have updated to 1.1.1

The file, if it matters, is http://www.playindead.net/shake3.mp4

 

Actually, if I copy the same file over to the iPhone with iTunes, it plays just fine. And it will play sometimes streaming off the website in Safari, but any other task with the phone, such as turning the phone horizontal makes it reset. Seems like it's right on the edge of what Safari can handle, perhaps.