public virtual string ModuleId
    {
      get
      {
        return this.Description.GetHashCode().ToString();
      }
    }

GetHashCode() returns different values depending on if run in 32 or 64 bit.

"CKEditor (HTML)".GetHashCode().ToString() returns either -880775851 or 1931734265 depending which env you run it in.

Edit: to clarify - if you move your database from one server to another, or if you do change your iis etc etc, there is a chance that the environment will change. It might not be obvious to find the problem with correct editors not showing.