When I fly through a dense area such as a major city I can go very smoothly but if I turn around and and make a second pass my frame rates drop off considerably. Is there such a thing as a cache or some other item that is being overloaded?I am running an I5 650 Processor with 8 gigs of memory with most sliders at pretty much max.Also when flying a fast plane the first minute is extremely smooth but after that I get random pauses. A slower aircraft goes quite well but even then heavy scenery causes problems. I am well aware I can back off on the sliders and improve performance but flying over bare ground isn't much fun. Anybody have any ideas?