I am using rdesktop 1.6.0.
I was facing problem wih audio redirection when connecting to windows 2008 server.
I come across the following link  which says sound redirection without drive redirection does not work with 2008 server.
I am enabling drive redirection to get audio redirection and it is working.
But what I want is a patch kind of stuff which automatically enable drive redirection or remove this dependency,
so that there will be no need to manually enable drive redirection to get audio redirection.