What video source do you use (2D, 3D SBS)?
If you use a 2D input and want to convert to 3D, first try to put the resolution in 720P on the PCH, than try to press the pass through button first and then the 3D button for 3D DLP.
When you use a SBS video, you have to see two pictures side by side half, than if you press the button 3D source for 3D DLP, you must have to see in 3D.
I think what ever the source you use, you must put it first in 720P.
Have you try in anaglyph? Maybe the problem is with your DLP link glasses (Are they compatible to your projector?)