720x480 resolution and overlays in display driver

Hi,

I have added support for 720x480 resolution in my display driver.
Everything else works fine except the overlay. When I play some media
file I get wrong overlay information. E.g when I play a media clip at 24
bpp destination pitch is given as 2304 (which tells that the destination
width is 768 instead of 720) also when I full screen the video the
destination width comes out to be 640 while it should be 720 i.e the
width of the desktop.

Not just this, when I play the video the color key value is all over the
place. I mean the color key is not present in just the rectangle of the
video player instead it is spread over the desktop. It seems that the
color key value is also copied using some wrong information like
destination pitch and width.

I think I am missing something. Do we have to specify the supported
resolution for DirectDraw as well? Thanks in advance

Regards,
Mudeem