The thing is, Verstappen got paid too late for his services in the previous season. He received a million dollars though, but that's beside the point in his view. Therefore he demanded, the day before yesterday, a bank guarantee for the whole season, otherwise he wouldn't drive.
Seatholder Jan Lammers is not in the position to give bank guarantees, because he doesn't have a spare million laying around for that and thought the contract would be enough to get his money. For extra assurance, the A1GP organisation was willing to sign that contract as well. Verstappen (i.e. his manager Huub Rothengatter) nonetheless thought it was better to withdraw from the race, leaving 70.000 paying fans without their hero (not mine though).
More on
http://netherlands.a1gp.com/currentNewsDisplay.php?id=1942
