Black Level on Plasma Display

I own a SONY 42" Plasma Display. Although the colors scenes look great, the darker scenes, wich demands a better level of black, seems a little too bright. Even after professional calibration, the black level doesn't seems too good. I was thinking of changing my DVD Player to try to get some improvement (my DVD Player is the Harmon Kardon DV-50 - with progressive scan). Is it possible to improve the black level of the display by changing the DVD player? Which are the best black level DVD players?
I have been reading a lot lately about Plasma and I am seriously thinking about the Sony PFM 42B. The one problem I keep reading about in reviews is that so far Plasma still cannot keep up with the best of the other types when it comes to black level. I don't get the impression that a better player will change that. If you find out more please let me know. Is the problem severe? I saw a demo at the show in New York, but not for long enough to evaluate it well.
I don't think the problem is severe, but it is noticeable. In long dark scenes, you have the sensation that the black is kind of "bright". My bedroom wall behind the Plasma seems a lot more darker than the scenes in the Plasma. Somehow you can feel that this is not the darker a black scene can get. I heard that some dvd player have a better black level management than the others, but I'm not sure how good my DVD Player is in such matter...
Most plasma displays suffer from the inability to display black- most display only shades of gray. It has only been recently that some manufacturers have been able to address this problem. The best display IMO is the Runco 42cx and 50 which use an outboard scaler for video processing.
This is the problem for the plasma displays for computers also. I deal with the graphics industry and that is why the professional color people use the crt for hi end color work. There was not display out there that did as good a job as the crt.(even the 3k apple display. Not going to get much better in the next year or so.
Being "In the Buisness" I would have to concur, black levels are a problem. Upgrading your source will not cure your problem. Panasonic and Pioneer have the best black levels that I have seen so far, I have not seen the Runco so I cannot coment on it. I would also make sure that your cables are up to speed so to say and that your power source is stable. Cheers!