rdesktop sound problems

I am using rdesktop in GNOME to connect to a Windows XP Pro machine, and cannot get the sound to play except on the Windows machine. I have tried both of the following options for calling rdesktop with the same results, the sound plays on the Windows machine but not through rdesktop.

rdesktop -g 90% -P -r sound -0
rdesktop -g 90% -P -r sound:local -0
rdesktop -g 90% -P -r sound:remote -0

Any help or suggestions would be greatly appreciated!