Greetings David-e,
Thanks for following up with us. Please try connecting to the projector with either the VGA adapter or the HDMI adapter, and doing the following:
- Right click on your Desktop.
- Click on Screen Resolution.
- Click on Detect (attempt to connect to the Projector).
- Select the Projector (should be listed as 2 while 1 is the Surface RT's screen).
- Click on Advanced Settings.
- Click on List All Modes in the bottom left.
- Set the mode to 800x600.
Let me know what happens.