I'm using Suddenlink Cable through a Scientific Atlanta 8300HD STB/PVR, into a Sony Wega 55" LCD projection HDTV.

I'm having an issue with some channels coming in at 16:9 and filling the entire screen while in Full screen setting, while others coming in at 16:9 don't, and I have to change the Aspect setting from Full to Zoom to fill the screen.

Why is this? Is there a solution, so that all 16:9 input fills the screen automatically?

When a TV program which is "filmed" with a SD 4:3 aspect ratio camera such as most daytime shoes and many news programs is trasmmitted using a 16:9 aspect ratio HD resolution black, grey or blue side pillers are added to the video before it is upscaled to 720p or 1080i.

When a TV program which is "filmed" with a SD 4:3 aspect ratio camera such as most daytime shoes and many news programs is trasmmitted using a 16:9 aspect ratio HD resolution black, grey or blue side pillers are added to the video before it is upscaled to 720p or 1080i.
Yeah, but that's not what I'm referring to. The not-full-screen shows were shot in, and are being shown in, 16:9 aspect, with black all around. Changing the aspect setting to Zoom enlarges the image to completely fill the HD screen precisely, with no distortion and no over- or under-scan. There is no 4:3 involvement at all.

The normal black bars all around with an HD resolution channel occurs when 16:9 content has been letteboxed for display in 4:3 aspect ratio and then this is upscaled to HD resoloution. I see this often with commercials on HD broadcasts but I have never seen if for entire programs.
What channels are you haveing this problem with? Do you always have the problem with these channels?

The normal black bars all around with an HD resolution channel occurs when 16:9 content has been letteboxed for display in 4:3 aspect ratio and then this is upscaled to HD resoloution. I see this often with commercials on HD broadcasts but I have never seen if for entire programs.
What channels are you haveing this problem with? Do you have the problem with these channels?
Some specific examples right now, as I'm composing this:
-- "West Wing" on Bravo.
-- "Animalia" on local PBS channel
-- "Amazing Sports Stories" on FSN
-- "CSI" on SPIKE
-- "Raising the Bar" on TNT
-- "A Haunting" on Discovery
Etc., etc., etc.
-- PLUS various commercials in between shows that are in the normal 4:3 format with black bars on the L/R only, while other commercials are 16:9 with black all around.

So the problem relates to both commercials AND full shows/movies, while being interspersed with 4:3 content.

I just tried Raising the Bar on TNT HD on my cabl3 system and have no problems.
What channel number is TNT HD on your system?

I just tried Raising the Bar on TNT HD on my cabl3 system and have no problems.
What channel number is TNT HD on your system?
I'm sorry, it wasn't on TNT HD, just TNT.