I just picked up a 32gb PB and I LOVE it. I had to exchange my first one because the battery was unusually dying within the day with no use...
Anyway, I got my new one and whenever I unlock it from "sleep mode", the screen turns on fine, but the screen appears to be very dim. Then after about 15-20 seconds of playing with it, the screen becomes significantly brighter...
I didn't have this issue on my other PB that had the battery problem...
I am having a similar issue where my screen is at low brightness(which is what I have it set too) but then it jumps to a higher brightness for a few seconds before going back to my setting. At first I thought it was the automatic dimming feature but I don't see why it would have increased the brightness for only a few seconds.