That said, I have a friend who applied for a visa from the French to attend the Paris Air Show a few years ago to order some planes from Airbus. He was denied, despite a whole host of paperwork and invitations from EADS.

Reason? "You must provide company registration and bank statement of inviting company".

A few phonecalls at consular level later the visa was quickly issued, but it does show how bureaucracy can sometimes go a bit crazy.