1Ds2 jpeg vertical banding ... normal or something wrong?

i recently got a 1Ds2, i always shoot in jpeg (since 99% of my use is snapshots)
i noticed that when zoomed in, the jpeg shots have vertical bands (absent in my 5D2)

is this because of the ancient jpeg engine or is there something wrong?

[note, i have not tried RAW yet, simply because i rarely shoot RAW]

here's the crop

Whoa. Shoot a high ISO shot in low light, see if it jumps out. It may only happen with one particular lens, and it can occasionally be caused by interference from a nearby electrical source. If it is interference that one time you will be unable to recreate the problem.

I had a MKIIN with banding and it was returned immediately for replacement.

edit:

it happens on any lens and any location

but it seems to be more apparent at low ISO

When I caught that problem, it was most easily detected in a pushed low light shot, and by that I mean in this scene shot at ISO 3200 I moved exposure up two stops to make it really obvious.

it's there even on high ISO, but the noise hides the banding
that's why i use the 1ds2 outdoors or with speedlite and the 5d2 anytime else.

in case people are wondering: i've sent an email to the local canon with a pic attachment btw, but i put up this thread to get some extra comments/opinions

Push hard. What I was told is my options were refund or refurb.