I have my xbox on an HDMI cable to my TV, and the component cables it came with are going to my Bose Acousitmass speakers. I'm loving the seround sound and the HQ video, but every 10-30 seconds my screen on my tv goes black for 2-3 seconds. The sound goes away too. Now this is a huge problem for a gamer like me.
System names if your wondering-
Xbox 360 Slim
Bose Acoustimass 6 series 3 (brand new - just bought it from Costco today)
Panasonic Viesa (or Vieza) HDTV. This is a couple years old
The hd,I and component cables work perfectly when they aren't hooked up together.
And I am running the newest software on everything hooked up.