Yeah give your coals a chance to set first. Try that first. I had the same issue with temps and now I can easily get both of my drums up to temp. And it will take some time. If your cooking low and slow and extra 10 minutes to get up to temp never hurts.
It is much easier to catch target temp by coming up slow than coming up fast and missing it and trying to bring it back down.
And @ BBQDane, good call on 3 bolts for BBQ racks. My one drum I used 3 bolts and I am sure they are not even and the rack does not wobble. My BP EDS that I built uses 4 bolts and the rack wobbles a tad.