Door and pushback problem solved - for me anyway

Fellow captains,Like many of you, I've had problems with getting doors and pushback to work. I've assigned single keystrokes to the functions instead of the usual CTRL-E and Shift-P commands, but still would never get the doors or pushback to work.But today I stumbled onto a workaround.If I load a saved flight with the PMDG aircraft already selected, doors and pushback won't work.If however, I reselect the aircraft - even if I use the same aircraft - the doors and pushback work as designed!So, my hypothesis is there's something in FS9 that causes it.