1-2 shift is accomplished by the low-reverse band releasing (if applied) and the front (also called 2nd gear or kickdown band) being applied by the servo and over-running the rear roller clutch. It doesn't sound like the band is applying fast enough to cleanly clear the rear roller. I usually set my front band to 72 in.lbs., then back off 2 turns. I don't know what you had it set at before, but I think you mentioned that it got better when you reduced it to 2 1/2 turns.