What I tried to do, is just converting an image sequence into a quicktime file, this has happened in earlier versions of AE and right now I'm using CS5 and it was still the same, so I'm thinking it might not be a bug.
In my case, I'm trying to convert an image sequence of 82 frames in open exr format, what I did in AE, is drag and drop the sequence folder into AE project folder, and then drag them into the Create a new composition button. I then use Ctrl+K to get to composition setting and set all the correct settings, in my case for a test sequence I did, 720px 480px, Square pixel and 24 frames per second. then I used Ctrl+shift+/ to add to render queue sed output Module> format: quicktime movie and format option to either HD264 or MPEG,(I've tried almost any other popular formats with same result). made sure the Render Settings to be everything correct, it usually follows and the default is as expected. after setting output to: file name, hit render. that's every tiny step that I did.
when I open it up using quicktime, I'll see my frame becomes 66 frames instead of 82 what is going on?? since I know it's an AE problem, and I knew if I convert these in either apple shake or in final cut pro would work, and currently I don't have a Mac, I told a friend to experimented on the same sequence for me. And it turns out perfectly as expected, I see 82 frames in the final image.....
I believe I've followed tutorials on how to do this, so it's not a method that I invented for converting or rendering image sequenced, how come AE can't do something so simple?? if anyone can help it will be deeply appreciated.