capturing over firewire with MaxMsp/Jitter, compared to PD/GEM

This is more of a general question, but I'm finding that Jitter and PD are handling a firewire signal much differently when I try to record video to disk and I'm trying to understand why this would be the case more fully.

I'm using a 3ccd panasonic video camera that records a 720 x 480 wide (which translates to 853 x 480). In PD the capture device recognizes and reads this image properly and saves out a really quite nice signal that, when played back in quicktime has a native and correct resolution of 853 x 480. The image quality is really clean and isn't stepped on and I'm not seeing jagged edges on curves or stepping happening on diagonal lines.

When I switch to jitter the camera capture settings are identical, but no matter what I do, the quality of the image takes a major major hit. The image quality is degraded and shows stepping on curves and lines and the resolution, regardless of what combination I try (720 x 480, 640 x 480, 853 x 480) they all record poorly.

Is this a firewire issue with Jitter? Is this an area where PD/Gem are able to adapt and perform with greater strength? I'm really frustrated by this since I'd love to have my programming stick to one software program, but as much as I find the instability of PD to be aggravating, I find the hit I take in image quality with Jitter to be equally perplexing. Can anyone shed light on this? I'd really appreciate any insight from people who are working with/around this issue.

Thanks
nico