Importing HD MPEG-2 into Toon Boom

I want to import video footage that I have edited in Pinnacle Studio and saved as and MPEG 2 HD 720p at 1280 x 720 screen size. TBS cannot import in this format and gives an error message [E 1216]. If I save my edited footage as MPEG -1 file type then TBS is able to import the footage without any problem. However I lose a lot of resolution this way. Is there a solution that will allow me to maintain HD quality?

The resolution of the bitmaps that you see in the camera view is reduced to help performance. This is only for previewing. On export, the bitmaps should appear at full resolution.

As for the format, Toon Boom Studio should be able to open any format that the QuickTime player can open.