The preset resolutions on the display do not include 1152 x 864, so you'll have to adjust the size yourself. According to the specifications, there IS a size adjustment on the display control menu.
The preset resolutions are:
1280 x 1024 @ 60, 75 Hz
1024 x 768 @ 60, 70, 75 Hz
800 x 600 @ 60, 72, 75 Hz
720 x 400 @ 70 Hz
640 x 480 @ 60, 72, 75 Hz
The display should auto-adjust to any of these (you could try 1280 x 1024 to confirm).
Page 26 of the manual (attached) shows a "Custom Scaling" option that allows you to set "Fill to Screen" as one of the options. Since 1152 x 864 is the same aspect ratio as 1024 x 768, this should look fine with no distortion (Note that the display itself is actually a 5:4 screen; but 4:3 aspect ratio selections look fine on it).
