out of memory

fsx stopped.....computer has run out of available memory...change settings and restart.....my framerates were 20-30....am i missing something?...maybe i had the mesh too high?...the only change i made...fsx-vista-accel
Intel core 2 Quad Q6600 2.4g
Asus P5k3 delux wifi edition
2gb ddrIII 1066 mhz Memory
eVGA 8800gt 512mb pci-e video
Intel core 2 Quad Q6600 2.4g
Asus P5k3 delux wifi edition
2gb ddrIII 1066 mhz Memory
eVGA 8800gt 512mb pci-e video