Yeah, I am currently streaming Pandora, holding the phone with my left hand cradling the bottom, while replying to this post, all on 3G. I haven't been able to get the bars to drop either...
Cradling from the bottom isn't the problem. Holding it from the sides without touching the bottom, and without a case, is the problem. Remember that the antenna is the metal on the sides.
The problems seem to arise from covering the seams so as to say where the frame pieces are connected. If the seam is not covered or touched by hand, there should be no drop in the network. Seems like the antenna's shorting out when the seam is covered by hand.
A small piece of scotch tape should do the job as far as avoiding this problem goes until one can get hold of a cover
