I purchased an LN-T4571f on January 1st which had PB in the serial number and had 1013.1 firmware, discovered the stutter problem within the first week of ownership, and have been reading these posts ever since. When my set begins to stutter, it appears like every other frame is being dropped out or skipped. I first thought the problem was my DVD player beginning to act up (Oppo DV-981HD), but ruled that out by testing the player on a few other TVs. I have witness stutter with AMP on all settings (including off), though it was very rare and short-lived when AMP was off (with AMP off, stuttering only happened twice and lasted about 3 seconds or so). I've watched several movies with AMP on low, and each stuttered anywhere from 2 to 6 times during an entire viewing.
AMP on low, I noticed that the stuttering usually begins right after a scene change and can last anywhere from a couple seconds to over a minute, but it usually clears up if I momentarily pause the player during an episode. I also found that I can sometimes induce the stutter by quickly pressing pause/play a few times in rapid succession. Unfortunately I do not yet have cable and I am frighten about how poor this TV may act when do I get it (based on some other experiences here).
So now I have 2 days left to return this set to CC. I have previously been through 3 other brand LCD TVs, all which had hideous panel problems, but this one is absolutely perfect short of the stuttering problem. Also, the picture quality blows away all of my previous LCD experiences. Not to sound pessimistic, but I worry that there will not be a firmware upgrade to fix this problem since it was mostly fixed on the first sets with 2xxx firmware, which have now been out for a few months. It seems to me that there has been plenty of time to update the 1xxx firmware if the stutter fix was that simple.
The return clock is ticking and I wish I had more time to wait for the magic fix. Another almost
satisfied Samsung customer...how sad.