Low rpm hesitation

Hey guys.. got a problem with my 1994 320i M50b20tu. At low revs or at idle when I stomp on the throttle the revs drop before accelerating. Ive checked for vacuum leaks 3 times already.. dont seem to find any.. what could be the problem?

Here is video of what i mean. Thanks guys

Sluggish revs: http://youtu.be/6LRezeHa-H4

Low rpm hesitation