I have this error:
qaz blue:~$ banshee
** (/usr/lib/banshee-1/Nereid.exe:10124): WARNING **: The following assembly
referenced from /usr/lib/banshee-1/Nereid.exe could not be loaded:
Assembly: gdk-sharp (assemblyref_index=4)
Version: 2.12.0.0
Public Key: 35e10195dab3c99f
The assembly was not found in the Global Assembly Cache, a path listed in
the MONO_PATH environment variable, or in the location of the executing
assembly (/usr/lib/banshee-1).
Looks like gdk-sharp isn't installed. Do you have libgtk2.0-cil installed? Also, how did you install Banshee?