Goofy stuff with TV/Kickdown Cable on 700r4

[BigRed]

I was having problems with my old TV cable binding on my Suburban (700r4) a couple of weeks ago. So, I bought a new one and replaced it and set it per Mike's and the 700r4.com instructions. Worked great. Well, two days later, it was shifting high on me (into 2nd at 20 and 3rd at about 38). So, I reset it per the instructions and all was fine again. That lasted for about 3 days and then same problem again and I reset it once more. Well, that lasted another 3 or 4 days and then today it happend again. I was on the freeway and had to kick it down to get around some slow-poke (first time I've had to kick it down since I installed it). I then exited the freeway and all was fine. Then, when I accelerated from the first light, it wouldn't shift into 2nd gear at all. Well, it might have eventually, but I wasn't going to let the RPMs get too high to let it. So, I pulled over (with wife, 2 kids, wife's grandmother in the truck) and reset the cable once more. Thank goodness I had my mechanix gloves with me or would have burnt myself pretty bad! After that, all is fine. However, I have no confidence it will stay that way because of my past experience the last week or so.

What is going on here? Could I possibly have a bad cable or is there something maybe wrong with the Throttle Valve assembly itself? Please adivse on what I can do to resolve this?

Thanks!