OK, need some more help...

Other than the low idle that I need adjusting, the other issue is the shifting. The 700r4 transmission was rebuilt less than 12k miles ago and I never had this problem until the other day. http://iroczone.com/forums/images/smiles/huh.gif

When I'm getting on the highway, with the shifter in OD, it seems to fail to shift from 3rd to 4th for a few seconds and then finally does so with a jerk. If I down shift from OD at that speed and then shift back up to OD, it doesn't happen. However, while this happens, I lose power (not electrical power) but "power", power. http://iroczone.com/forums/images/smiles/mad2.gif

The tranny is rebuilt, I did have the transmission mount replaced and new cat's put on. All lines/hoses are also connected and tight underneath the hood/chasis. Throttle valve cable is correct. I do need a transmission flush as it is reddish-brown and burnt smelling, but would that be a probable cause for this?

Any ideas or suggestions?

The correct adjustment of the TV cable is an absolute necessity to the long life of both the 700-R4 and the 200-4R. If the cable is not adjusted correctly, the tranny will fail. If the fluid is burnt, I have a feeling that the cable was not adjusted correctly. 12K miles is not a lot of miles. Too little to burn the fluid, unless something else affected the tranny, like the TV cable. My recommendation is to take it to a tranny shop and have them hook gauges to it. That will tell you if it's just fluid or clutches or something else is letting go. Of course, change the fluid first. You may get lucky, but unfortunately, with only 12K miles on the rebuild and burnt fluid already, I think it's going to need another rebuild. Here is a website that offers an "EZ" TV system. With this you can't go wrong. Good luck.
http://www.tvmadeez.com/

OK, need some more help...

I do need a transmission flush as it is reddish-brown and burnt smelling, but would that be a probable cause for this?

Any ideas or suggestions?
A high possibility. I would find a reputable transmission shop to check it out. You need to have an on hands inspection w/trans pan dropped and inspected.There are just too many possibilities to find the answer here.