I asked this question on another thread back in the day (of course, I no longer remember which one) and never did get much of an answer- I mailed it in to the Sage and also got no answer, so I'll put it up again.
A drunken master's improvised weapon class feature says that it deals unarmed strike damage plus its own extra damage- does that also bypass damage reduction as an unarmed strike would? i.e. if you were to hit someone with a tree branch, would that be bludgeoning and magic if you were high enough level monk to bypass magic DR? I couldn't find anything in the FAQ or errata to say one way or the other.
I would say yes - Drunken Master is a PrC specifically designed for monks, so it would only make sense that the abilities it grants would be an extension of their natural abilities (unless specifically listed otherwise).
Sounds right to me...
-Kurocyn