New Eos 400D dissapointments - banding issues

I have a panasonic Fz50 which I love,
sure high iso isn't it's specialty,
but the lense is much faster than the kit lenses with the 400d,

and the Optical Image stabalisation gives tack sharp images even down to 1/6 of a second.
so I haven't really needed high ISO,

anyhow I bought a 400D to give me the ability to shoot in high iso and still get nice prints.

But it seems to have some very bad banding issues.
I'm not sure if this is normal, or if I got a dud,
can someone please confirm for me.

Smaller version of origional

crop 1

crop 2

Are these normal, and the 400d just not good at high ISO or is there a problem here?

I have about one hundred shots that all have similar artifacts like this shot in a few different locations.

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I love taking photos of the beautiful things God's made, the closer you get, the more beautiful they appear.