I guess 1440x990 it's the native so you should define a new 1440x990 in P96 and start the fun part of playing with edit mode :S
It took me 2hours to be able to make my 23" Samsung LCD/TV to play smoothly with P96@1360x768 using edit mode blind (using cursor keys+crt+shift etc)
I used 1440x990 in a previous Samsung 19" just fine mate so you only need to experiment with a new mode from scratch.
