http://bugs.winehq.org/show_bug.cgi?id=32225
--- Comment #3 from Austin English austinenglish@gmail.com 2012-11-15 13:33:39 CST --- (In reply to comment #2)
Why does it have to work like that? What would we have to break in order to fix this? I looked for some discussion/explanation of this behaviour, found none.
You had odbc32 set to native,builtin. When loading native failed, it fell back to wine's builtin version. As you found, setting it to native only enables your desired behavior.