A relative newbie is lost on HOH vol II and +EV plays in MTT´s

[GeoffH]

There's a couple reasons to fold hands that you think are ahead, or +EV in both 1-table and Multi-table tournaments.

If you are close to, or on the bubble for the prize pool(this is more the case for 1-table SNG's) and your stack is not under a great deal of pressure from the blinds, it can be correct to fold hands like AKo to a large raise, since if you are only a slight favourite, you are giving yourself a 45% chance (rough estimate) of losing and being the most likely to NOT finish in the money. If you throw the hand away with no money invested, you have at least one other player who is more likely to finish out of the money.

In a large MTT this can be the case very early in tournament. While you want to play big hands aggressively, if someone else overbets into you in the early stages of a long tournament, it is not the goal to be going into coinflip situations, even when you think you may ahead and therefore +EV. It is the exact oppossite when you are in the money and at the final table.

So like Jonny5 noted, it's mostly REAL money considerations that would cause you to fold +EV hands. The unique structure of tournaments means that in situations where the prize pool is very close or very far you take less risks like the ones you described.