I bought a canon 7d about a week ago, recorded some footage at 1080p (29.97fps). Now, the 7d puts a quicktime h264 compression on the footage, which is difficult to edit with. So, I downloaded a program (MPEG Streamclip), which can convert the footage to DVCPro HD 720p60.
When I play the converted .mov, all is well - and it shows up as DVCPRO HD (720p60) in it's info.
Problem is, when I import the footage into AE, it's being read as 960 X 720. I open up the composition settings, and it confirms that. Also, the pixel aspect ratio is set at HDV 1080/DVCPro HD 720 (1.33).
It should be noted that this is not happening in Premiere.
DVCPRO HD stores 720p images exactly as you've described -- 960 pixels wide, at 1.33 PAR, instead of 1280 square pixels.
You can work with what you've got by clicking the "Toggle Pixel Aspect Ratio Correction button" -- it's underneath the composition viewer window, and looks like a rectangle with a double-headed arrow above it.
Alternately, you could transcode to another format that uses the full raster with square pixels.
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting RenderBreak Blog - What I'm thinking when my workstation's thinking
why convert to DVCPro HD 720p60? if using FCP you should use Apple ProRes 422 (HQ) for progressive material and keep all your acquisition settings the same. If your in Premier you should transcode to XDCAM and the edit will be seamless. Your files will triple in size using either format because your essentially uncompressing the h.264 format which makes processing easier.