Ok. When ever you connect a different player to a display or even the same player via 2 different connection types you should (re)calibrate the TV to match the input of the player. There's a whole forum here dedicated to display calibration and there are discs like Digital Video Essentials that explain the basics of display (video) and HT audio calibration. Even the basic calibrations are essential for you to get the best (and proper) picture displayed. Or you can have a professional calibrate your TV.
What I was getting at in my post was that the A2 may be sending different video "levels" than the TV is expecting, for example sending PC video levels instead of "studio" video levels. This has been an issue for Toshiba players for some displays, most of them being DVI input displays. The issue is that "black" for PC levels is at 0 and "black" for studio levels is 16. So if the display outputs black (or doesn't output anything actually) when it sees 16, it will output a little bit more brightness for 17, a little more for 18, etc. But if the input video has been set to send 0 for black, 1 for a little brighter, etc. 16 should be a fair amount brighter but the TV may be expecting 16 to be "black". Basically, all dark video information will be displayed darker than it should be. I'm not say this it the case for you, but it's a good chance.
In order for a lot of this to "sink in" and if you are interested, you need to do some digging here and maybe at the Wiki site about digital video. PC RGB, studio RGB, YCbCr, brightness, contrast, component video, "blacker than black". The Digital Video Essentials DVD has some good tutorials while explaining calibration. It's a lot of stuff to digest, biting off a little at a time is the best way.