Further, I have reinstalled all dependencies of libmono-wcf3.0-cil:
http://packages.ubuntu.com/precise-updates/libmono-wcf3.0-cil
libmono-corlib2.0-cil (>= 2.6.3)
Mono core library (for CLI 2.0)
libmono-security2.0-cil (>= 2.6.7)
Mono Security library (for CLI 2.0)
libmono-system-messaging2.0-cil (>= 2.6.3)
Mono System.Messaging Library (for CLI 2.0)
libmono-system-web2.0-cil (>= 2.10.3)
Mono System.Web Library (for CLI 2.0)
libmono-system2.0-cil (>= 2.10.3)
Mono System libraries (for CLI 2.0)
All return as already installed latest versions.