Cactus V4 banding issues on the 5D?

Hrm, my Cactus V4 radio triggers just arrived today.

Reliability-wise it's been near-perfect so far. My main issue is that it seems to be introducing some fairly severe banding with my 5D.

See top of the image here:

http://photodecal.org/gallery/main.php?g2_itemId=46122

Has anybody else come across this issue? I've read in a few other places that it is specific to the 5D. Wondering if I should exchange it, or if anyone knows of a way to fix (there's a modification out for the V2.. but haven't seen it for the V4).

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