transmission surging and hesitating

Car was bought new in November 2003. I reported to the Dealer, who told me to use high octane gas. He also explained that this is "designed in to make the car "green"". I always use 92 gasoline. The problem gets much worse if lower grade is used. If the battery is disconnected for 24 hrs, it resets and works smoother; but the problem returns in a week or two (adapting to the Driver). I have heard that they came up with the firmware upgrade for 2004-2005 ES330s and will see if I can find somebody to upgrade mine. Currently car has just about 280,000 miles on it. Four years ago I did the transmission overhaul which fixed other (slippage) problems but not this one. During a "Toyota sudden acceleration" mayhem I even wrote a letter to Toyota suggesting that controllable surging and hesitation of the automatic transmission coming from its firmware trying to make the ride smooth, along with the engine control firmware may very well be a systematic root of the sudden acceleration problem. Toyota answered to the letter by saying that they do not take advise from a Customer (of course, they know better - it's a floor mat).