High Iso problems with D3

Hello Everyone. I was wondering about the Cmos Sensor on the D3 and the way it interacts with the camera under certain conditions.

I have a Pentax K20D which seems to suffer from a problem that some may be experiencing here which I have seen. At the very high Iso of 6400 on my K20D there is a horizontal pattern that emerges that corresponds to brighter pockets of light that hit the sensor. If I am mistaken about the D3 having a similar problem at 128000Iso and 256000Iso then I appologise.
I have not seen this same problem with the D300 even with pushed pictures.

Anyway, I was wondering if Nikon have found a way to surpress the problem and/or if its fixable in PP via any noise reduction (which seems to reduce it somewhat in Noiseware Pro) .

Thank you for your time.