My info tells me that they have tried to increase the rent on both the hangar and an on-site warehouse to rather more than you'd expect to pay at Heathrow, as well as a bunch of other highly suspect decisions.
I guess there must be a huge queue of companies waiting to come in there - enough that they can afford to turn away business. Either that, or the existing management are simply demonstrating that they are as good at pissing Scots taxpayers' money up the wall as they are Infratil's...