Air Craft Textures

I have the PMDG 737-800/900 software with several liveries and have been flying with great success with good textures and frame rates. A few days ago when I selected the outside view, my program seemed to freeze with the outline of the aircraft on the screen, but no aircraft textures. After 30 to 40 seconds the aircraft textures started to fill in and movement returned. When I switched back to the cockpit view, all was well until I went to outside view and the samething happened. The problem is consistant now.When I first start FS9 and the default 737 comes up, the outside view works normally. I selected several other FS aircraft and also had no problems. When I select a PMDG aircraft from the same menu, the computer hangs up with all sorts of difficulties. When I select a previously saved flight, I can install the PMDG aircraft and flight of choice and fly normally until I select outside view as described above.Has some part of the PMDG program somehow become contaminated? Any suggestions would be appreciated.AMD 3200+A7N8X-X mbFX57001G DDR2100 RichR