I thought about the following case last night in bed, when I couldn't fall asleep. The situation is as follows:
You are sitting at a 1$/1$ cash table in a casino that takes a 5% rake with a 5$ cap. You are in the BB with some random hand (say 36o) and it gets folded to the SB who calls (with, say, 56) and you check. Both you and the SB had 100$ stacks before this pot.
Flop: AhAsAd
Check/Check
Turn: Ac
Check/Check
River: Kh
SB bets 99$ (all-in). BB ?
Now if BB folds, he loses his 1$ big blind. But if he calls (and if he calls he, he can be sure that he is never beat), in doing so he creates a 200$ pot allowing the casino to take the 5$ rake, before the remaining pot of 195$ gets split and the BB gets 97.5$ back. Therefore, by calling the BB loses 2.5$ instead of 1$ he'd lose folding.
Hence, the above spot is a spot in which it is better to fold, although one knows that one will never lose the hand should one call.