Very curious, have you tried to:
1) change/update the graphic card's drivers?
2) change the risolution/colour depth of your FS9 in the video setup?
3) tried to delete the fs9.cfg?
But more importantly:
Has your PC still a little LSD remained? I wish to try it at least once in my life.

There's but one real cure for human stupidity. It's called DEATH.
At the moment mourning the assassination of sarcasm and irony for the good of the "higher".
Proud FSIX user. Active user of FS98, X-plane and novic