Depending on how you positioned the projector, you
may need to change the projection mode so your images project
correctly. 
- 
Front
(default setting) lets you project from a table in front of the
screen.
- 
Front/Ceiling
flips the image over top-to-bottom to project upside-down from a
ceiling or wall mount.
- 
Rear
flips the image horizontally to project from behind a translucent
screen.
- 
Rear/Ceiling
flips the image over top-to-bottom and horizontally to project from
the ceiling and behind a translucent screen.