I have been searching for a solution to this for some time now.  Whenever I attempt to install the Yannick Lavigne Dassualt Falcon-50 in FS9 there are diplay problems with the model.  Notably the landing gear to not display and the airstair door will not close. It works perfectly in FS2002.  Now, someone said he operates this aircraft in FS9 with no display problems at all.  I don't what he might be doing differently than me. I am currently running the falcon-50 panel in a falcon-900 but I really want the falcon-50 model and no one has made one for any fs version other than Yahhick Lavigne. I suppose because his would be real hard to equal or exceed.  If anyone knows what could cause display problems like that in FS9 i would sure love to hear the pointers.  Also, it is gmax, which should work as it was redone that way for FS2002. I'm thinking maybe there is an aircraft.cfg line that could be changed to correct these issues. Thank you.