I agree with K-lo here, spot on information.
A very similar and sometimes confusing (to some dealers and even some floors for some reason) presents itself when a player has less than a full blind and is all in in the big or small blind. For instance, blinds are 200-400 with a 25 ante, the big blind only has 175. First to act makes it 1200 and everyone folds including the small blind. The player can only win from each other person what he began the hand with, so his 25 ante goes into the main pot along with everyone else. He only has 150 left now so his 150 and the raiser's 150 go into the pot. The small blind had 200 but only 150 can go into the main, so the raiser gets that 50 automatically.
It's the kind of stuff that if you take your time and work out you'll figure it out, but it doesn't happen very often so people just don't think about it.