How Can You Get Sony Vegas 10 to Render a Droid Video for Youtube

[WHS]

I cannot get Sony Vegas 10 to render a .3gp video taken by my Droid X for Youtube.

At the very end of rendering it reports a failure and states the cause could not be determined.

I use
-the main concepts mp4 codec,
-progressive YUV
-1280 by 720
- I let Sony match the frame rate and tried forcing the frame rate:
-tried 29.97 fps (forced) and 15.15fps (sony detected 15.15fps)
-44.1kHz/256kbit/s audio.
-I push the bit rate to a constant 50mbps way bigger than whats required so Youtube will have a clean copy to encode.