Optoma HD70 DLP Projector "square rectangle screen" Questions

...square: One verticle side shorter than other I have Optoma HD71 PROJECTOR. The image from the projector is not a true rectangle image. The verticle sides are fine and the top horizontal side is also ...

...square/rectangle it should be. The picture was a bit off before I changed the bulb, but now appears to be worse. It looks like some Jawas are going to walk out of the screen offering me droids...do ...

rectangle but it is not a typical keystone issue as it is square on left side and top but low on bottom right and skewed low on top right. It is a school projector on a mobile whiteboard, supported by