I saw the same behavior with 3250hd / Samsung DLP. I went back to using component because I was tired of continually unplugging the DVI cable to correct the problem. I'd be interested in any solution you find.
I live in Lexington and have also been waiting to see if the "test" channel between HBO-HD & Showtime-HD will become WLTX-DT. I noticed the guide seems different, I'll check tonight to see if it's any slower.
Also, 4 people at my workplace have 3100HD boxes, so hopefully the people on this site don't represent 80% of TW's HD subscribers in Columbia.