The problem ended up being the transmission ready to shred....a little while after that post it started slipping etc....I had the transmission rebuilt with heavy duty converter and clutch packs. One of the clutch hub snap springs was broken. After the rebuild the cruise dropped a few times then"healed" itself after the computer reset...thanks for the head up Tom

Be cautious, I had the same problem and had my trans rebuilt. 2 weeks later it was back to doing the same thing. The TC would lock unlock lock unlock and 40 to 50 mph under mild accell same from 65 to 75. Had a diesel buddy tell me to pull the alternator fuse and see how she runs....did that and guess what, Ran like it was new. needless to say I had the alternator tested and it failed, replaced it and all the battery terminals today and she runs better than the day i bought it. Bad diodes in the alternator threw interferance to the TC, my Adrenaline, and my TPS. $150 and shes fixed instead of $4k

My 99 I had did the same thing after some research and helpful tips from matt bozarth at ats he figured it was doing a 4th gear hunt witch was easily fixed by bypassing the tossed from the ecm straight to the pcm it fixed the hunting problem if I can find the diagram I will post it.