I have been looking at buying the one that Costco has here( Optoma EP738 DLP Home Theatre System) and was planning to mount it on the ceiling . I see some places sell telescopic mounts for the celing . Can these projectors be mounted right on the ceiling or does the unit itself have to be postioned in the middle of the screen and beam straight forward ? Like is it ok for the beam to point down towards the screen from a 7 foot ceiling ?