Interesting. A few other things that come to mind that might contribute to its slugglishness is the rotatoing weight of the wheels and tires, the DC's wheelbase, and the fork's rake and the bike's trail. Rake and trail (trail is a function of the HTA, wheelbase and rake) affect how a bike handles, from really stable (some would say sluggish) to really responsive (some would say twitchy). Although I wouldn't expect a cyclocross bike to be overly stable in its handling, it depends on what fork they used with the frame.

In any event, I'm sorry the bike's not working out for you. It's such a shame.