I've been having a lot of problems with packet loss lately (ever since the 3.5 patch) and it sometimes causes an odd occurrence.

In a dungeon earlier today I activated Enochian, but some packet loss happened during the time between activating the ability and getting the associated buff. I know this because I was running monitoring software alongside the game to check. The net result here was that Enochian went on cooldown but I did not get the buff.

So that timeline is:
1: Push Enochian
2: Enochian cooldown starts
3: Lose a packet or two
4: Nothing happens

So now I have no Enochian buff (and therefore can't use Fire4/Blizzard4) but the ability is on cooldown anyway and I have to wait a full minute to do it again.

NB: This has happened with things that aren't Enochian too. Basically any skill or ability with a cooldown will trigger its cooldown but not its effect if the wrong packet gets lost in level3's dumpster fire of a network.