What are your film fit settings on your camera in Maya?
My fit resolution gate is set to - Fill.
and all the fit offsets are set to 0.
It is a default camera. The only parameter that I changed is the focal length from 35mm to 25mm.
I tried changing it and it didn't help.
I think I figured the cause of it but I still don't have a solution.
I found this in AE manual: Pixel aspect ratio and frame aspect ratio
It speaks about a scenario, like mine, where I have a composition with square pixels
which has a resolution of a standard non-square pixel, and it try to fix it from 640px to 720px.
But as I mentioned in my first post, I can't just resize it to my original resolution.
I read the "Baking and importing Maya data". I already have success with importing data from Maya
on different projects that don't have the resolution width of 640px.
Is After Effects creating 2 comps on import? A square pixel comp at the 640 wide and also a non-square comp at 720 wide?
It creates a single comp.
If I set my project to 641x360, render few frames and then export it to AE (baking cameras, nulls) everything works just fine.
But I want it to work with 640x360.
Hmmm...weird. I don't have CS5.5 but you could check the intepretation_rules.txt file to see if there's a rule for Maya scene files that you can alter. Doubtful, though. I may be missing something (hopefully I am for your sake), but if not, it seems that your best bet might be to re-render your frames at 641 and crop the comp in AE. Possibly a bug with the .ma importer/loader code?
Edit: On second thought, rendering at 642 would probably be a better idea (cropping 1 full pixel from each side).
In the end I decided to re-render my scene with the final resolution (1280x720 - doesn't have the auto resize issue).
This is something I would have to do anyways... it just came sooner.
Thank you for your help TimeRemapper!