Scientists have unshakable beliefs in things that can't be proven. Like everything having a logical explanation for example. They're not even open to the possibility that there are things that are illogical.
This is a staple of faith.
Most scientists would say that the believe in things that can't be proved, but for which there is strong evidence. For the most part, I agree with them.
I think scientists make a good point when they say ID and other forms of creationism are not science, because science deals with the natural world, not with the supernatural. It's taken me a fair deal of debate to understand that point.
Where some scientists cross from being scholars to believers in a faith is when they say science is all there is: There is nothing beyond the natural world. Even that, though I disagree, is not necessarily foolish or closed-minded. See the comments above on Daniel Dennett, for example.
Where it gets off the tracks, IMO, is when it starts proclaiming anyone who believes in God or gods or the supernatural or anything not part of science as fools and charlatans. Then we're heading over into the secular equivalent of Pat Robertson nutcase territory. Or, at least, annoying obnoxiousness.