Actually, I think this is probably a good snapshot of the current state of play. Perry got hit hard on the Gardasil and immigration issues, and a dip in the polls was to be expected. What will be more telling is how the polls look in a couple more weeks - will they start trending down, or will they recover? I don't dismiss polls just because they have information I don't like (unlike the supporter of a non-candidate I know), but neither do I take the results of a single poll as definitive. Rather, I look at the trends - what happens over several polls from different pollsters? If they all show movement one direction or another, then that is probably how the race is moving at that time.
You only single out Palin supporters. However, there are supporters of all candidates who dismiss polls that they don't like and they support polls that they do like.
That said, there is no way to prove that a poll this far out from an election is accurate. Because of that, polls this far out are at risk to being inaccurate.
I'm no fan of Perry, but that said, I think that a poll that shows Perry seven points behind Obama at this point in time, are not credible.