on ubuntu 9.04 cannot be loaded

[jedioetzi]

luca@luca-laptop:~/Work/development/third-party/bb$ debianpackagemaker

** (DebianPackageMaker:11445): WARNING **: The following assembly referenced from /usr/lib/debianpackagemaker/DebianPackageMaker.exe could not be loaded:
     Assembly: gnome-sharp (assemblyref_index=6)
     Version: 2.20.0.0
     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/debianpackagemaker).

** (DebianPackageMaker:11445): WARNING **: Could not load file or assembly 'gnome-sharp, Version=2.20.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f' or one of its dependencies.

Unhandled Exception: System.TypeLoadException: A type load exception has occurred.
  at DebianPackageMaker.MainClass.Main (System.String[] args) [0x00000]