Extreme Lag Upon Entering Combat?

[Deejay]

Hey, I downloaded someones UI pack earlier (Indiegarona's to be precise), and everything was fine until I entered combat. It gave me extreme lag spikes and the game started ti freeze, making it completely unplayable. This hasn't ever happ[ened before I downloaded the UI pack. All addons are up-to-date. Any ideas?
Sorry for there being so many threads from me, it's just this UI is gorgeous and it's being hindered by therese small factors -.-