Black bar flickering

[volcomsocal]

Here's what I own:
Panasonic 42" plasma TH-42PX60U
80 GB PS3
Direct TV HD reciever

Hey guys. I'm relatively new here, but I've owned my plasma for 3 years now.

The problem I'm having, and have been having for months now, is when I watch SD movies or Blu-ray movies that have vertical or horizontal black bars, those black bars flicker. If I watch tv, whether HD or SD, I never see any flickering whatsoever. I checked the 2 HDMI cords on the back of my tv (one going to my PS3, one going to my Direct TV HD reciever) to see if they were crimped due to the lack of space because my plasma is wall mounted. Both HDMI cables seem very short on space and crimped but especially the one connected to my PS3. But like I said, there is no flickering problem when I watch tv. So I thought the HDMI that's connected to my PS3 was worn out.

I bought a new HDMI that goes from my plasma to my PS3, plugged it in, popped in FRIENDS (vertical black bars), and still had the flickering problem. I also popped in a Blu-ray that has a 2.40:1 aspect ratio (horizontal black bars), and the flickering was there as well.

I'm completely stumped as to why this is happening. Is the problem my PS3? Has anyone ever come across this problem on their own setup? Help!

Thanks in advance.