I don't think (a) is the cuase of (. To my recollection, hitters have been hitting all of his mistakes in the zone as opposed to last year when he could get away with making a mistake on his curve, because hitters were locked in.
In other words, it appears Beckett's 07 has made hitters honest on his breaking stuff and when he can't get that over, he gets in trouble.
I think expectations were very high for Beckett this season especially since coming off of such a great postseason, but this is simply a regression and a little bit of bad luck. Nothing more, IMO.