As stated, there shouldn't be any time in a NL game where you cannot wager as much as you want, if you have yet to act on that street.
That being said, sometimes they simply get it soooo wrong.
I was in a tourny once and had KK. UTG raises, I 3bet, UTG 4 bets. I go to 5 bet all in, only to be told that I can't re-raise because UTG's raise constituted the 5th raise.
They not only misapplied a LIMIT POKER ruling into a tournament, but their reasoning was that the small blind and big blind each counted as "one raise" towards the cap of 5 bets.
But I suspect your situation involved the more common:
Guy A bets 1000, Guy B goes all in for 1400, You (having not yet acted) are told you can't raise because Guy B's bet isn't large enough to reopen the action. This should, of course, be irrelevant because you haven't yet acted on Guy A's initial bet. You should be free to raise.
I haven't had my coffee yet, but I think the legal minimum raise you could do in this example would be 2000, min raising the last legal raise.