First off, a big thank you to this awesome site, SLI rules!
The shifter on my 4EAT was so bad that it wouldn't even shift below the "2" position and was having a tough time shifting into park. So I searched around on the site and found out that all the linkages and whatnot are exposed (and somewhat hidden) to the elements and get all nasty, corroded, rusty, etc and need some TLC now and then... So I jacked up the beast and went to town with the P.B. Blaster, WD40 and white lithium grease. HOLY CRAP! what a difference! Before finding out about what the actual problem was, I was worried that my transmission was going out on me. But thanks to the info here on this site, it's all good. :-)
So, if you happen across this post because you're looking for possible fixes to your shifter issues... Get up under there and soak that sh*t with some break-free and grease it up... Its super simple, and after all the lube and grease work their way into all the little nooks and crannies, the difference is night and day.