My 850, 1994, has similar symptoms. Sometimes, after stoplight, it starts on 3rd gear and the flashing orange arrow appears (flashing arrow signals a problem, non-flashing arrow is normal on winter mode). It gives a fault code 222, which suggests a break in solenoid s2 circuit. Instructions how to read fault codes can be found on this web site. A list of codes for transmission problems can be found in http://au.geocities.com/ozbrick850/. There you can also find a jpg of volvo 850 tranny which gives you a hint where the solenoids are located. Information about 850 trannies is difficult to get because official Volvo repair rather changes the whole unit. Even Haynes' book does not give codes for tranny problems. However, the solenoids should not be too difficult to change since they are located in the tranny oil pan, in front of the engine (left side). I'll probably try to do work by myself. I'll just first take the car to Volvo guys so that they can plug in their tester and make sure that my diagnosis on the basis of the fault code is correct. There is also a very helpful article in Transtec magazine (1998, vol 5, issue 1; to be found at http://transtec.com/). The guys there dismantled a Volvo unit (Aisin-Warner 50-42), took pictures and compared it with similar Opel products.

Petri