Hi Cameron, had just a FPS drop again, while flying around with the C400 today. First thing I did was to select / de-select the full screen checkbox in x-plane rendering settings menu – without success (Started x-plane with de-select full screen checkbox). So lets try to answer your questions: 1. The FPS drop occured after rd. 70 min. flight time after departing from an airfield. Had done several landings on other airfields before without any issues. 2. The FPS increased to good 40-50 fps when zooming out in chase view, drop back to 19 fps when zooming in the plane. Also had 21-22 fps in 2D cockpit view. 3. Always occur in 3D Cockpit and chase view 4. yes, no improve My specs: iMac 2.66 GHz Intel Core i5, 8 GB RAM, ATI Radeon HD 4850 512 MB, Mac OS X 10.6.3, X-Plane 9.45 BTW: After reloading the plane I had another issue. The soft keys of the Garmin on left side of the cockpit have no longer works, so I could not switch to another mode. Anybody else had this? I hope this was helpful for you! Frank