Well, I'm not so stupid to accept any bet on that . In the mean time this seems to be the faulty Thread : Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 mac.xpl 0x298b0278 AIRNAV::CDU::FMS4200PageManager::FKUP() + 52 1 mac.xpl 0x298b2a5a openGLCDU<PPLcrj14::OverlayGauge>::handleNonDragClick(int, int) + 2520 2 mac.xpl 0x29925dac PPLcrj14::OverlayGauge::handle2dClickCallback(void*, int, int, int) + 660 3 mac.xpl 0x29925e3b PPLcrj14::OverlayGauge::handle2dClickCallback(void*, int, int, int, void*) + 45 4 XPLM 0x16f85333 XPLMDisplayMouseClickHook(int, int, int) + 161 5 com.laminar_research.X-Plane 0x00868b1f XPPMouseClickHook(int, int, int) + 335 6 com.laminar_research.X-Plane 0x00a60a74 xplane_window_delegate::mouse_down(void*, int, int, int) + 260 7 com.laminar_research.X-Plane 0x00ba3bf9 -[WIN_OpenGLView mouseDown:] + 121 8 com.apple.AppKit 0x91edaa21 -[NSWindow sendEvent:] + 6968 9 com.apple.AppKit 0x91ed5a0f -[NSApplication sendEvent:] + 4278 10 QtGui 0x2b933dec -[QNSApplication qt_sendEvent_replacement:] + 76 11 com.laminar_research.X-Plane 0x0038c1a7 WIN_event_loop_once + 343 12 com.laminar_research.X-Plane 0x00ba485c WIN_run_app + 44 13 com.laminar_research.X-Plane 0x0057c6ed main + 1501 14 com.laminar_research.X-Plane 0x003f7239 start + 53 Actually installing on my LapTop (F...ing Optimus card with an nVidia Quadro 1000M) SO I'm gonna run the test on Windows From Demo Install. FMS4200PageManager::FKUP Is exactly what I do to provoke Crash... This is only intuition, but I'm pretty sure that fault is located at low Level API (but Which one ?? :P ) I keep Testing and will come back to You if've any further valuable info to help Diagnosis. Thank's anyway...