I have been having problems with the GSX having several glitches, such as the stairs extending through the aircraft
They don't, provided (of course) that if you use an airplane which is not already internally supported by GSX, you make a configuration for it using the editor provided with GSX. All clearly explained in the GSX manual.
the baggage tractors not visible
They are perfectly visible. But again, if you don't configure your airplane (if it's not already supported by GSX), and the door's are not correctly set, some vehicles will not appear.
with the driver floating in the air while driving the tractor, and other glitches.
This doesn't happen either. If you have *parts* of an object missing, it's a problem of your video settings, and the solution is usually as follows:
- Update your video driver
- Reset your video driver settings to default
- Reset the FSX settings to default, by removing the following file:
%APPDATA%\Microsof\FSX\FSX.CFG
This will force FSX to rebuild a new config with all default settings. After doing this, be sure you apply the HIGHMEMFIX tweak in the Addon Manager, save the settings and restart FSX.
If this still doesn't fix it, be sure you don't run FSX into any of the "Compatibility" modes. Every checkmark in the Compatibility tab of the Properties for FSX.EXE should be off.