Choose "Select All" first then "Copy" before you Edit > “Add to Selection and Scale”.
Also YouTube might not accept the video if you just use "Save As" then Select "Save as self-contained movie"
I had to re-open the final file and use "Export" "Movie to Quicktime Movie" from drop-down menu.
Options: Compression H.264
Quality: High
Key frame rate: 24
Encoding mode: multi-pass
Dimensions: 720 x 450 (Current) my size choice.
Here's what it looks like:
http://www.youtube.com/watch?v=-ChNoyADzw8