http://bugs.winehq.org/show_bug.cgi?id=22032
--- Comment #7 from Stefan Dösinger stefandoesinger@gmx.at 2010-06-06 04:21:57 --- Edward, you don't have the right gcc to build a Wine that Steam likes.
First, you need binutils 2.20 Then compile gcc from SVN(maybe 4.5 works too), make sure it's using the new binutils Afterwards, re-run wine's configure with the new gcc *and* the new binutils. It should print that support for "ms_hook_prologue" is found.
Then recompile wine and the overlay dll should attach successfully and you'll run into the problem described in this bug. It used to work when I made the gcc changes - dunno what broke it.