sometimes i wish to change aircraft whilst sat on the tarmac and so use Alt > load aircraft. Since i reinstalled my fs9 noticed that the aircraft previews in here are just blacked out. No preview whatsoever, can anyone shed some light on this for me please?

Check the anti-alias on video card. If it is too high reduce it. This worked on friends set-up and I read the info someplace here on Avsim.

If using Nvidia drivers, try switching from full screen to windowed view in FS also, it worked for me.