[Muine] unhandled exception

[z <nostalgiafed gmail com>]

i'm using ubuntu and today i upgraded my gstreamer and related packages
to the newest available from the official apt repositories. after that
muine returned unhandled exception during start and eventually it would
just stop after that error.here's the output i get in the console. some
parts may not be exact copy&paste, because they're translated from
the locale i'm using.

zbrox trillion:~ $ muine

Unhandled Exception: System.Exception: Unable to initialize the sound backend:
Unable to create GStreamer Play object
in <0x00092> Muine.PlaylistWindow:SetupPlayer ()
in <0x00228> Muine.PlaylistWindow:.ctor ()
in <0x0039a> Muine.Global:Main (string[])

can you help me with that?
thank you in advance,
rostislav