Have you got secured with the appropriate screws the BVision on the BPPC?
Connector is ok but since it contains MANY signals, it kinda sux if some pin isn't making a nice and firm connection.
I also had in the past some artifact issues, but most of times were either a non-screwed BVision or heat issues that were solved putting 2x 40x40x10 fans and heatsink to Permedia and the 2 large chips
