just FYI guys... i tried everything but the navone filter for this fix and nothing worked. After reading another thread on the same problem I found that my problem was the ABS sensor on the rear axle above the differential. I guess it was either worn out or shorted. After I unplugged it I have had ZERO downshifting and/or lock/unlock problems. This seems to have cured it. For all you out there who have tried to solve this problem to no avail, I suggest you unhook this sensor and see if this solves it. I replaced the APPS, did the suncoast rewire, installed the bd filter, flashed the pcm and nothing helped. I had ordered a new pcm and had it on the way when I tried this out of frustration and it fixed it. I finally like driving my truck again. I hope this can help someone else out there.