Lags when looting and submitting quests

A question in the round, is it normal that it lags or even completely stalls when you loot something or finish a quest?
I mean it's 1-2 seconds where just nothing happens during.
Actually I don't have this problem with Icecrown. Only here...
I hope that I will be helped :)

Not really, that sounds like something caused by an add-on.

I had this thought too, but since it all works wonderfully on Icecrown I didn't test it out. UNTIL NOW. And lo and behold, for whatever reason, it was due to an addon :D
Thanks for the answer