Terrain.dll CTD

Hey,I have FSX and SP1 installed and Iwas just wondering if you have heard of this problem:Whenever I click Fly Now, the flight starts to load and then suddenly half way through loading, Vista saysFlight Simulator X has stopped responding. It then closes. Here is the error report Problem signatureProblem Event Name APPCRASHApplication Name fsx.exeApplication Version 10.0.61355.0Application Timestamp 4643ee0aFault Module Name terrain.dllFault Module Version 10.0.61355.0Fault Module Timestamp 4643f2aaException Code c0000005Exception Offset 0003c35cOS Version 6.0.6000.2.0.0.768.3Locale ID 2057Additional Information 1 bf48Additional Information 2 ba98a1c05df33f07b3f27ef5dcb2d751Additional Information 3 bf48Additional Information 4 ba98a1c05df33f07b3f27ef5dcb2d751I have not installed any Add-Ons for FSX eitherRegards,Alex