I never had a problem with Maya showing crisp images in the viewport for my image planes but Max seems to be a bit of a pain and seem to come out a littl grainy.
I found on the area that a guy created a DirectX shader and applied his reference through that but Ive been trying that and only get a black plane. http://area.autodesk.com/tips/make_a_clear_blueprint_in_max
I set up the configure viewport to match bitmap as closely as possible at 512 and 1024. Also on my work computer it saves these settings so when I open max back up they are there. At home in Max it doesnt seem to be saving these match bitmap as closesly as possible. And as im sure you know you need to restart Max for the settings to take effect.
Any help would be great guys. Thanks