BMW Repair: transmission on 95 525i, transmission filter, filter change

Question
I bought my 525i two years ago from a dealer.  has a clean record two prior owners 1 was a corporate the second private.  bought the car with 82,000.  has had no work on it except my regular oil & filter change.  I did replace the plugs at 100,000  and two months ago replace the transmission filter,  now I have 155,000.  My question.  when I put the car in reverse to back out of the garage sometimes it takes a few seconds to engage into reverse. and now when I brake and come to a stop at an intersection at times the car seems to go into neutral  I've been driving in S3 lately which seems to reduce the problem at stops..... I filled the transmission with new fluid when replacing the filter.  I belive I have the right amount of transmission fluid.  would it be and electronic part on the transmission?  because once I'm on thr road the car runs great!
any ideas

Answer
The problem is in the electronic solinoid pack, somehow the computer isn't telling the trannie that you are about to come to a stop, whereas with the sport mode it has a different shift strategy and therefor can better predict the stops.
It's also likely that changeing the fluid could have caused some problems with the clutches.  Have a diagnosis run on the transmission, it should be pulling codes, if not it could possibly be the computer itself that is the problem.
-cheers