Convert always produces 640x320 output

[redorblueguy]

I have an .mp4 file generated by Windows Movie Maker that is 1280x720. VLC plays it just fine and at 100% zoom, it displays in the correct size. The Codec Information says that it is 1280 x 720.

I used the Convert/Save so that I could enable the Image Filter and change the gamma of the video.
It converts, and I get a new .mp4 out that plays just fine EXCEPT, that it is always 640 x 320!

I created a custom profile for the conversion.
Encapsulation is AVI
Video Codec is MPEG-4
Bitrate is 3000 kb/s (although I have tried as high as 8000 with no change)
Frame Rate is "Same as Source"

Originally on the "Resolution" Tab of of the profile, I set Scale, Width, and Height all to "Auto".
Now, I have tried setting the Scale to "Auto" and the width=1280px, height=720px
or the Scale to 1 and the width/height to auto.
None of these make any difference.

I also tried using H.264 and MPEG-2 as my output codecs and the behavior is the same. I always get 640 x 320
even though the input source file is 1280x720.

Is there some other setting somewhere that limits the output video size?