yeah... i've taken the tests in the kaplan and barrons books/cd's. and, there's stuff i didn't agree with, too.
so, keep an eye out for that sorta thing... it's still a good tool to have overall, though.
here's the thing: if you take the tests, you have to anticipate (or at least be prepared for the possibiltiy that) the actual DAT score will be lower.
if you notice the mistake AFTER you've reveiwed and are just checking solutions, then no harm done. HOWEVER, if you're actually LEARNING material off those solutions, ok... then you're screwed.