Thanks to everyone for offering ideas. Once I noticed that it was not just Las Vegas but also missing airplane terminals at many airports and some addon airplanes whose liveries would not be painted on, I concluded that I needed to do a complete reinstall of FSX. I had previously tried that without success, but this time I followed a tip that says don't reinstall SP! or SP2 until, after installation, you have run the program once. Once I did that and then installed SP! and 2, everything worked fine, both in LV and at the airports. There was a lot of addon scenery and addon airplanes to reinstall , but it all worked out and kept me off the streets and out of my spouse's hair. Prior to the reinstall, I returned my Nvidia Inspector settings to their default values. I have left them there and it didn't seem to make a difference that I could notice. After hours of fiddling, this had a happy ending!