In versions later than 2.0, there is not usually supposed to be a pause when doing any operations like shuffling or inserting. The only time this should happen is when the cache is severely stressed.

However, in 2.0b7 I agree that I have heard an unusual number of pauses when inserting, order-tweaking, or shuffling/unshuffling. I'm going to make sure this one is on the internal bug list.