I've noticed some chopping off at the theatre! Very often, I'll notice some picture on the curtains to the sides of the screen and in the area above and below the screen! I assume they want to make the image as large as possible, so they zoom it just a wee bit, figuring that there's nothing of interest in those areas.
Consider also that there's a bit of overscan on a lot of TVs. When using a test pattern such as DVE or the one on HDNet, I notice that there's something like 3% or something on each side that's cut off. So it's possible that you may NEVER see the full image! (Maybe if you watch it on a computer monitor.)
cheers,
supervij