Shifting & bogging

Hi all! I've been having some trouble with my '94 GP SE w/170K and am hoping to find some help here. Here's the problem: My car takes off just fine, however, when it shifts from 1st to 2nd gear it shutters a bit, then the RPMs drop about 500-1000. It shutters (slightly less) at each shift point after that. Also if I'm cruising at a steady speed and go to accelerate, the RPMs begin to rise, then drop about 1000-1500 RPM and the engine boggs. I have to give it a LOT of gas to get it to downshift (and it shutters when it does) I figured I'd change the tranny fluid & filter first, but no dice. Now I'm not really sure if it's a tranny problem or the engine. Anyone have any suggestions?

I found this on 60DegreeV6.com and it sounds a lot like my problem:

http://www.60degreev6.com/TSB/TSB24-4T60E.html

I was just wondering if this is a common problem? Should I be looking for something simpler or what?