Recaptcha and System.Web.MVC

Exception occurred while populating cache, Will set RazorDataTypeModelTypes to null so that this error remains visible and you don't end up with an empty cache with silent failure.

The exception was System.Exception and the message was Unable to load one or more of the types in assembly 'Recaptcha, Version=1.0.5.0, Culture=neutral, PublicKeyToken=9afc4d65b28c38c2'. Exceptions were thrown:

System.IO.FileNotFoundException: Could not load file or assembly 'System.Web.Mvc, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified..
   at umbraco.BusinessLogic.Utils.TypeFinder.FindClassesMarkedWithAttribute(Assembly assembly, Type attribute)
   at umbraco.BusinessLogic.Utils.TypeFinder.FindClassesMarkedWithAttribute(Type attribute)
   at umbraco.MacroEngines.DynamicNode.TryGetMember(GetMemberBinder binder, Object& result)