Intrade breaks the first rule of derivatives

The first rule of derivatives is "A derivative contract has a clearly specified expiration". This allows a fair valuation of the contract, including probability and cost-of-carry calculations.

Now Chris Masse reports:

I have been inundated with complaints from InTrade traders, since Christmas. Here’s the problem. InTrade traders tell me that the expiration dates for the Bloomberg and Gore announcement contracts have been extended —at InTrade’s whim. The contract statements, I’m told, said they would expire on December 22, 2007. At this time, InTrade did not settle the bets and the expiry date was changed to read “November 2008″.

This is a good way to scare away liquidity, thereby weakening the exchange's predictiveness. Can someone at Intrade HQ say "strategy"? Anyone, anyone?

I'm not sure whether I should suspect incompetence or conflict of interest as the greater probable cause for this. Neither scenario breeds confidence.