Have you tried adjusting the picture size in both the player and the television? Aspect Ratios can be changed with either, and sometimes it's a combination of aspect ratios that may help you get the desired picture.
Also, it may depend on how the picture was recorded, and what aspect ratio it was recorded in.
I've just got this player, which plays DVDs very well. I am disappointed though that when it plays every DVDR of TV programmes which I have recorded on a Sony RDR-GX350 recorder, the picture is squashed - a widescreen picture looks like a 4:3, with the picture filling the screen from top to bottom, but with blank bars on each side. I am playing it through a Samsung LE37B550A5 TV. Using the picture aspect control does not cure the problem.
When I play the same DVDRs on my laptop, on a friends Playstation, or Sony Blu Ray player there is no problem.
I can't find an answer in any of the manuals, and would be grateful for help.