I have had video corruption problems with MP4FastStart and Youtube, so I recommend (and use) AOA MP4 Patch, Drax, or simply the MP4Box command line to do this task.

Interesting. Seems like an odd oversight on the part of the makers of Vegas.

No, Sony didn't write that codec - they just pay a license to include it in the package.

Vegas writes moov atom at front for H.264 encoding. But I think not yet in version 8. It's an option in the render dialog of Sony AVC and MainConcept AVC. So not an oversight.

"..No, Sony didn't write that codec - they just pay a license to include it in the package..."

I assume the makers of Handbrake didn't write the codec either but Handbrake has a web optimization option - as I understand it the sole function of "web optimization" is putting the moov atom at the front.

Handbrake does a whole bunch of things that Vegas Pro 8 won't, or won't accept.
Handbrake puts out a new build every night; VP8 ceased development four years ago. It's just something you're either going to have to learn to live with, or upgrade.

Ok, dumb question time.

What on earth is a 'moov atom' and why should I even care? I never heard of that critter before. LOL!

Simply, it's the header information that must be read before an mp4/mov video can start playing. If it's at the end (the default), the whole file must load into memory before it can start playing. If located at the beginning, your file can start playing right away, and load the buffer on the the fly..

Thanks Vidmus for asking the question and for musicvid10 for providing the answer, very illuminating. Where on earth do all you wise folk learn this stuff?