I'd be especially interested in a listing of upstream-projects Nokia contributed to. (and a short summary of what was contributed and why)

The perception about Nokia is that
a) They're morally evil because they're big and successful
b) They bought Trolltech to take QT away from the community
c) They're experimenting (in niche markets) with open source, trying to use it only to reduce costs but not playing by the rules of the community

You can't change this just by saying "no, we're not evil. at least not all that much." - You will have to accept this is what people think. The only thing you can do is add d), e) and f) to the list, all of which showing good things you do.