I have a 97 850R with 135,000 miles on it. I always flush tranny at about 25k-30k miles using mobil synthetic. I noticed that when I would let off of the accelerator at pretty much any speed that the car would immedietaly downshift. I thought it might be a bit low so checked and it appeared to be a little low. I added some. It went away for awhile and started again. Fluid level is actually a little high, I don't think enough to be a problem though. In fact the first time it happened the arrow on the dash started to blink. Any ideas would be appreciated.

Yesterday I let off the gas and it downshifted from 4th to 2nd at about 50 mph. Anyone?

It can't hurt to have someone take a multimeter to the speed sensor, to make sure it is running with in spec. I had a similar tranny issue about a year ago. It took 4 months or so for several shops to pinpoint the problem. A simple diagnostics test may not detect a bad speed sensor. It didn't with mine. Anyhow just a thought of what it could be. Good luck and have a great Christmas!

Jon