What did the Pakis know, and when did they know it?

The press (or media, if you prefer) is full of eye-rolling about the Pakistani claim that they knew nothing about bin Laden's compound a few hundred meters from the country's version of West Point. On the other hand, we are told that the CIA had been staking out Osama for weeks or months from a nearby house, complete with mirror windows and other implements of the spook trade. Now, if the Pakis did know about Osama, then they must also have known we were stalking him, right? That's a level of duplicity that leaves me breathless. I find it easier to believe that they didn't know about either one. Blue skies! -- Dan Ford