This is an old revision of the document!
Morty: I looked into this recently (End of 2011). Unfortunately, due to the buffering done on the server, this might start to “swing” (playback getting faster and slower again and again).
See: http://code.x2go.org/gitweb?p=x2goserver.git;a=commitdiff;h=147d22c44167b9b2d4afbdaf17262555a7af713b