I dropped mine down to 31 on the left, 30 on the right to try to add a little extra drag on that side to compensate for the sensitivity to road camber (I usually ride in the left lane, of course).
I had my V6 realigned under warranty and they said it had been out in the back. When I drove it again it was better, but still pulls left when in the left lane.
I don't think the differential tire pressures helped this any, but it was worth a try.
You may want to see my alignment thread. I had the same problem - several alignments (at two dealers and NTB) and it still pulled to the left if in the left lane and to the right in the right lane. The last dealer finally spent two hours aligning it and got it dead on. He said it was "within spec" before, but the car is just too sensitive and needed to be dead-on. I'd take it back and have them set it dead on... then ask for the print-out. Mine tracks great now.
As for pressures, I run 31 now on the Bridgestone Serenity's.