We recently had local HD channels come on-line. About once per day one of them will go to a solid yellow screen, the audio can still be heard. It has never happened on any other channels or happened before the local HDs came on-line. This is using a VIP622. I am using a wing dish pointed for 61.5 for the locals and signal strength is about 50. After a bit the video is visible again. Not sure if it is happening on more then one channel as I haven't paid attention to that... will have to look next time it happens. Any ideas?