FSX out of Memory while using MD-11

Hello All,Sorry if this question has been asked. I recently upgraded my PC from XP to Windows 7. I did a complete hardware/software change. It seems everytime I used the PMDG MD-11 after about 25 minutes (10 minutes) of being airborne, FSX crashes saying it is "Out of Memory".I'm runningFSX SP 2Most recent PMDG MD-11 (With US Airways Livery) (just purchased the other day)FS2CrewActiveSky XRadar Contact v4Everything used to work in XP with no problems. It seems in FSX it crashes, I have lowered graphic settings, etc.... I'm losing my mind since I just bought this new PC, etc, etc. Everything runs great, but then after being airbone, it crashes. I've also lowered the Graphic settings, etc, etc.... PC SpecsAthlon II X2 245(2.9GHz) 4GB DDR2 500GB NVIDIA GeForce GT 220 1GBWindows 7 Home Premium 64-BitAny ideas or suggestions??? Thanks,Rob S.