Here's one for the experts.

I was watching a DVD last night in my new BlueRay player. (History channel disk - Greece:Engineering an Empire). And I couldn't get the image size right! It's a 50" screen, but was only displaying something like 42". normally I can push a button on the TV, and it'll zoom/stretch it up to 50" to fill the screen, but for some reason that doesn't seem to work with my BlueRay player.

I can go into the BlueRay player itself and make some adjustments, but it's cumbersome. And still the best I can do is stretch it sideways - but then my aspect ratio is off.

I'm using a HDMI to DVI cable for the connection. I tried using the component video plugs as well, but it didn't look as good, and still didn't let me adjust my size anyway.

Is this a compatibility issue? Should I get a different brand BlueRay player? Or is this the nature of the beast?

TV: Sony KF-50WE620 (2004 model). 50"projection. Best it has is DVI, no HDMI input. Monitor is 1080i, 720p, 480p, and 480i. (note it's not 1080p). The DVI input is EIA-861 compliant, using the HDCP protocol, if that means anything

BlueRay player: Magnavox NB500MS9. Just bought it new, but it's V1.1, and only cost $189, so probably not top of the line. I did set it at 1080i, so that it'd be compatible with my TV.