Is the problem only with QMacStyle? What you pasted, auba, states that it is the default style on the mac. Can you just set the default style to Plastique or Cleanlooks?
While I've built a qt application on/for OS X, it was in Cleanlooks and didn't use any stylesheets (and was quite awhile ago) so I'm unsure of the actual behavior. Can OS X run a different Style?
Bookmarks