Missing aircraft preview

Archived from groups: alt.games.microsoft.flight-sim (More info?)

Can anyone help with this problem?:

After installing a whole load of add-ons to my dad's FS2004 he has suddenly
lost the aircraft preview facility when selecting an aircraft. All other
drop-down menus are there and the selected aircraft all fly as expected,
just a blank pane where the rotating 3d preview should be.
I should add that every add-on installed without a hitch. They were things
such as GB Airports, PMDG 737NG, FlightSim Commander and FS2Crew. All
updates and patches were applied exactly as specified by the manufacturers.

Any clues?
Chips.

PC: AMD FX-55, 1GB RAM, Windows XP, Nvidia 6800GT, etc, etc.