What format export are you choosing out of mocha?
If you are using the After Effects Corner Pin export (supports motion blur) try re-exporting the mocha track as: AE Corner Pin (corner pin only). This will do only a corner pin and not corner pi with transform, scale rotation separate.
I believe this was fixed in recent builds of mocha and if you are running the AE version, you can purchase & upgrade to mocha AE v2.6.
Also – you may want to look at other workflows that do better corner pin rendering than the AE CP effect such as Red Giant Warp.
Lastly, there are other ways to get around scaling and resolution issues such as:
– scaling your graphic to perspective in AE than precomping
– than using “align surface” in mocha before exporting to apply corner pin data to precomped layers already in perspective.
Best of luck,
Ross
Ross Shain
Imagineer Systems
http://www.imagineersystems.com