A liberal dose of WD-40 on the transmission linkage seems to have improved the situation quite a bit.
I now remember a similar problem I had years ago. The seal where the shift linkage went into the transmission had gotten old and allowed enough moisture in to cause corrosion and the shaft would bind up. Fixed it with WD-40 then too. I guess it's true, if it should move and doesn't; spray it with WD-40. If it does move and shouldn't, use duct tape.
