My 01 ironman is doing the same thing. It "slips" into neutral in between 2nd and 3rd, sometimes seems to stay in a gear too long, and also has the " D" light out on the dash.

Tom, I'll be following your solenoid install, I thought that you said that you were going to do the install yourself. I will be doing the same,so let me know if you come across anything tricky.

Has there been any general consensus about what causes the D light to go out, seemingly at the same time? Creeg, did you ever fix your D indicator?