brensec,
I've noticed that if you have too many Megs in your game that will do it to. also don't remove any stock planes from the game or it won't load either. I did this by accident and had to reload the core files that allow for 3rd party Planes in your Reinstall list.
 
                                                                   Redsunfox
P.s  Plane in question F4U-1A, Got it confused with another Corsair. Just my Luck!

Thanks for all the suggestions people.

Although, the same advice does seem to be getting repeated over again. (Not that I don't appreciate input - Thank You).

To save everyone the trouble of going over the same obvious stuff over and over:
I have all the 'stock' aircraft installed. I have less than 60 planes in the Aircraft folder now (counting those with extra textures or more than one model etc).
I am aware of the possiblility of having another install of cfs2 to carry the rest of my planes but I prefer to keep them in a 'hanger'.

The problem concerning the 'two error messages' has been solved by removing some of the aircraft to a 'hanger' but I still have a problem with Free Flight and QC not initialising and the GC planes not working.
Hagar suggested a complete uninstall/install will fix both of these problems but I haven't got around to it yet (because I hate doing it - I have to remove and save all my add-ons first so that parts of them won't be overwritten) anyway........