tranny fluid reads low when hot, high when cold. huh?

[Wayfarer]

I'm trying to get my transmission fluid level just right after my indy waaay overfilled it on the last service (they had a brand new tech working on my car). It was reading about 3 inches too high on the dipstick and was foaming, showing bubbles, and not shifting right. So I'm now trying to get it back right on the money by draining a little, but there's a weird problem.

Ok, I've always thought that the transmission fluid level reads lower when cold then higher when it heats up and expands. However, I've been experiencing just the opposite. When stone cold, after sitting overnight, it reads right at the upper mark. Overfilled right? After all even the manual says it should read 12mm low when at shop temp. Problem is, after driving 20 minutes on the highway, parking on level ground, shifting throgh the gears, and waiting 5 minutes or so at idle, it reads low at an inch below the lower mark!

I've done this cycle all week just to double check myself, and it reads the same every time: at the higher mark when cold and an inch below the lower mark when hot. Am I going crazy or is there some explanation? I've never had a problem checking tranny fluid levels before and use the method as described above per the manual.

Car is a '92 300D 2.5 turbo, fluid is Dextron III ATF.

Thanks.