For the past two weeks I have not been able to load recently saved flights, sometimes AI planes sink into the ground and lean forward and sometimes the ground seems to disappear underneath my plane and the plane keeps on bouncing. Anybody had this? Should I reinstall, maybe even Windows.

I would try to remove the recent addons first before doing a full re-installation.

Thanks, I'll try that. The last thing I installed was the CLS MD80.

Use uninstallation methods recommended by the developers. Usually they have the uninstall done in the Add/Remove Programs folder at your Controls Panel.

Agree with Koosh. Try to find the problem by unininstalling things first or you might be back where you are kow aftre reinstalling. There is probably some addon messing things up [sometimes even a scenery layer change could do the trick, but still you would have to find out which layer]