This is a pretty hot button topic but here's a link to a good explanation of the study and both interpretations
Couples With Daughters More Likely to Divorce - ABC News
This study is one of those where the science is interesting but the interpretations get in the way. I don't like the douche-y explanations the scientists come up with...the first set is like, oh, it's because girls suck and dads hate tehm, then the second set is like, no, it's because women who have boys are doormats and not empowered. GAG. I think their science sucks and the whole thing kinda pisses me off.
I suspect, taking Trivers Willard into account, it's because people who are higher in social status have more boys, and it's a hell of a lot easier to stay married when you're rich than when you're poor. Mystery solved, where's my Nobel prize LOL