I have this same problem, but with Doctrine 1.2 instead of Doctrine 2.0.
I have a column with non-Ascii character in his name, and Doctrine give me this error when I try to select it :
Message: SQLSTATE: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '??_avanc?? AS c4__1 (...)
Where there should be the french "é" char instead of the double questions marks.