If you are uncertain whether you can trust the polls take a look at the margins of error.
Then decide for yourself if it is possible to have one poll with Kerry in the lead by 5, another with Bush in the lead by 5, on the same day in the same state, and have the margin of error on each poll be 3. You see this kind of thing repeatedly.
By definition, somebodys poll has to be more errant than the alleged statistical significance.