Scenery not totally loading

Hi All,
I wanted to repost this with the hopes of resolving the issue. Sometimes when I load KPHL the airport does not totally load. Building are missing, walls are missing but the roof is there. Sometimes I have to back out of the sim and reload it from the Xbox menu. It may take 2 or three times to load correctly. Any ideas would be very helpful. Does anyone else have this problem?

Thanks,
Jim

This happens to me often in MMMX, and sometimes there is no scenery at all, the aircraft just falls into nothing