I wouldn't say its necessarily the fault of the DCT used in the Focus/Fiesta, but rather a matter of it coming to market a year or two too soon.
CAFE plays a major role in "sqeezing every MPG" out of a particular car. It's an issue my Dad has been howling about for years. I'm all for progress, but forcing it too fast leads to these kinds of problems because there's not enough time to do thurough testing. Again, it's not always a Ford exclusive issue, everyone has to deal with it, except for apparently certain European automakers.