A few bullet-points on what I see as the likely contributing factors to the "women prefer jerks" meme:

• Romantic relationships often expose you to the worst of what people are capable of, and often end in unpleasant circumstances. If you ask someone about their most recent ex, they'll probably have more nasty stories than nice ones to tell about them.

• If the competition for the object of my affections is charming and confident, I'm going to say he's manipulative and arrogant.

• Making poor decisions about people you're attracted to, and systematically overlooking your partner's negative qualities, are well-established behaviour patterns in both sexes.

• Romantic underdogs feel like they bend over backwards to be noticed by women, whereas romantically successful men seem by comparison to put in relatively little work to achieve the same goal. This perceived effort is conflated with caring or worthiness.

It strikes me that the nice-guy/jerk idiom has an analogue in the Madonna/Whore dichotomy. I was going to comment on how I'd never seen mention of this in any of the numerous feminist treatments of "nice guy syndrome" I've seen, but a cursory Google suggests it's not a new idea.