The way I see it, free will is attacked from "above" and "below". From below because, you know, physics and stuff. And from above because we're always finding new mental illnesses and ways that our biology dictates some of the things we do. Kleptomaniacs are not free like other people; they feel compelled to steal stuff. We usually think they need to get fixed not punished. So maybe everything we do can eventually be explained by some subtle kleptomania like condition. We don't feel compelled to do stuff but the kletpo doesn't feel compelled either, he wants to steal.
We wish we could change out habits, but we don't just want to change our behaviour, we wish our desires were different. An obese person doesn't just want to eat less; he wants to stop being hungry all the time. It's easy for us to want to distance ourselves from our bad qualities but we like taking credit for our good bits but that's cheating. The thing is that we just are the collection of all these tendencies and desires, take them away and there's nothing left of us. I'm not trying to argue against free will, just that it's crazy to wish to be free of all the things that actually make us, us.
The reason we feel queasy about free will is the sinister sense of compulsion that it conjures, "but if determinism is a straightjacket it's one that fits so well that it allows every movement" (quote from Nick Fearn book).