One of our regular visitors ran in a severe problem after he had repaired FSX using the DvD’s. After starting FSX the sim crashed and with the event manager it indicates that simprop.dll (in the root of FSX) was the fault module. Before the repair action FSX was in SP2 mode (without Acceleration).
Resolution: After a repair action with the DVD’s you must run the SP1 servicepack as well as the SP2 servicepack. First run SP1 and then start FSX in default flight. Close FSX, then run SP2. When starting SP2 you will see no option to install….only to uninstall, so uninstall. After uninstall, re-run SP2 again, start FSX and your problem with simprop.dll is solved.