Microblogging applet crashes on Fedora 12

[Juan Saavedra]

When I try to update a Twitter status on Fedora 12, Gnome-Do 0.8.1 and plugin 1.1, it exits.
Now, executing from a terminal, I get this message:

** (/usr/lib/gnome-do/Do.exe:4709): WARNING **: The following assembly referenced from /usr/lib/gnome-do/plugins/Microblog.dll could not be loaded:
     Assembly: System.Web (assemblyref_index=9)
     Version: 2.0.0.0
     Public Key: b03f5f7f11d50a3a
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/gnome-do/plugins/).

** (/usr/lib/gnome-do/Do.exe:4709): WARNING **: Could not load file or assembly 'System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies.

** (/usr/lib/gnome-do/Do.exe:4709): WARNING **: Missing method UrlEncode in assembly /usr/lib/gnome-do/plugins/Microblog.dll, type System.Web.HttpUtility

Unhandled Exception: System.IO.FileNotFoundException: Could not load file or assembly 'System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies.
File name: 'System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'
  at Microblogging.MicroblogClient.UpdateStatus (System.String status, Nullable`1 inReplyToID) [0x00000]
  at Microblogging.Microblog.UpdateStatus (System.Object status) [0x00000]

The thing is that the plugin _does_ validate my account.
I installed gnome-do from the repositories, just in case.
Thanks.