Transmission Gear Slipping problems of the 2001 Buick Regal

Transmission had been sounding rough and slightly slipping going up hill in driveway soon after purchasing car as used. Car was said to have passed GMC 100+ point inspection. Transmission completely failed after about one week of ownership at 25,000 miles. Dealership and Buick responded very satisfactorily. Repairs completed under warranty. Repairs took about one week though a second attempt had to be made after transmission continued to slip slightly when going up hills, more noticeable at higher speeds and after a stop and turning left. Dealership reported the following on initial repairs: " . . . Fluid pressures ok. R&r trans (4t65e). Found input and reaction carrier assembly gears broken. Torrington thrust bearing failed, damaging gears. Replaced carrier, sun gear,input complete carrier,carrier drum, 2/1 band, bearing, filter, axle seal, gaskets as needed, flush case and related components to remove particles" subsequent continued problems resulted in the following repairs: ". . . . . Road test -performa diag. Isolated to valve body valves binding in their bores. Replaced transmission valve body and gasket,. . . . " car has functioned well since and as of 3/5/04.