Well the good news is that a patch has been applied to both vanilla wine and cxg (at the moment only advocates have access to the test version but it will be part of 7.1 when it is released).
I've ran several tests, with the standard 7.0 install I was getting a steady packet loss of 6% (I'll ignore a rather painful 42% loss walk around Bree :)), with the nightly build (20080719) I stayed at 0% and the only stutter I had was once when crossing the boundary heading into the Bree city zone.
So that problem is now solved, thanks to Stefan (I won't try to spell your surname) for pulling that patch in for me and thanks to Daniel Santos for creating it.