Wow that is fantastic spec, I think once you have acheive the optimum point you should get much better than me.
I am only getting 848 x 568 and possible 10FPS, although I have never recorded the time. I will do a series of tests next time. I am pulling apart the mount now so I won't be imaging for a while.
One thing to look out for that may be producing the artifacts, set the ISO 1600. It wont affect the picture or noise it will allow more light to appear on the screen, I think it is a electronic compensation for live view not real time.
Secondly choose the high possible shutter speed without over saturating. Take a few test shots before, My best images are using a higher speed, I did try different ISO setting but forgot to take notes, ( I was in a hurry) I believe if the shutter is to slow the atmosphere moves while taking the exposure.
Finally try set the white balance. APT doesn't have this feature, I use the canon utility to set the white balance. It makes it easier to process the colours after. I use Registax only for colour balance when the white-balance is a bit off. I use AVIStack to register and stack frames.
Have a nice weekend, good luck, I wish I was there but have commitments as usual.
