Hi Guys, I also had similiar problems when I installed as2012 (tats ,severe wind direction changes etc) and after several days of hair pulling and a few tickets to Damien, I discovered the culprit to be FSinn (whether on line or not).. Cure... Disable vatsim weather by default in the options box...go to add-ons(in the plane) FScopilot >Settings>Disable anything to do with weather (Cavok etc) and and reboot computer..I've had no problems with it since (jumping altimiters etc..) Hope this can be of some help Regards Fred