Full width page template for Twenty Ten

I’ve read other threads and followed the steps for creating a page template that goes full width rather than 640px centered using Twenty Ten. When I do so, it “works” in that the content is no longer centered and there isn’t a sidebar, but it floats and only goes 640px.

I know it’s reading the class because otherwise nothing would change, but I can’t seem to figure out why it’s not going full width.

*I am making these changes in a child theme. When I edit the parent theme CSS and change the single column css to 940 instead of 640 it works perfectly. Obviously I can’t keep this change because it will be overwritten, but I can’t figure out what I’ve done wrong.

Here is my child theme style sheet:

[code moderated - please use pastebin.com]

Thanks for any help.