I have a '99 BMW 740iL with a ZF 5-Speed auto transmission. Shifts beautifully 99% of the time but 3 times in recent months I have had an "odd occurence". I'll drive the car a short distance, park, and then a few minutes later hop back in the car and drive off. Again, this has only happened 3 times over about 2 - 3 months, but it's like the car won't upshift out of 1st. I have an excellent local transmission shop and I talked to them and they said that it's likely just the shifter linkage...if it happens again to "bump" the shifter with my hand. Well, it did it again today and sure enough I pushed the shift lever and found that it moved ever so slightly but immediately the revs dropped and the transmission shifted fine. It seems that it wasn't positively in drive. This never used to happen, and I know it seems minor, but now that it's happening periodically I want to fix it. Is this likely a simple issue with adjusting a linkage or is it possibly an issue with the transmission or transmission software? Thanks.