Had been discussing this problem before:
Well I finally got Wallace to a transmission place since I didn't have the time or resources to tear into the transmission. I was feeling pretty hopeless with the current KM132 tranny but got good news on Friday and went today and the friendly mechanic showed me the problem.
This spacer washer sitting towards the back had broke somehow and had gotten lodged into the transmission and had stopped all my progress at moving forward. Stuff had shifted as a result and I only had a couple of gears that were still inline enough to make the transmission usable. Luckily it only chipped a tooth on 5th gear, but nothing too terminal. Wallace is all back together now and is running like a scalded cat again! I got lucky on this one.