There wasnt enough intelligence to act on, that was the problem Clinton had as well. From what I remember, we knew there were terrorists in the country, we knew they were planning something big, and we knew it had something to do with airplanes, airlines, or airports. That is all we knew at the time. Also, before 9/11 the intelligence community did not talk to each other about anything. That was one of the biggest consequences of Clinton's intelligence spending policies. Agencies were basicly paid for results, so they didnt tell anyone else about anything they uncovered.
I find it funny that Bush is hammered for not acting on sketchy and incompelete intelligence before 9/11, then is attacked again when he acted on much better intelligence that turned out to be false. The hypocrisy of a liberal knows no bounds does it.