About FxCop

Question

hi,
 i try to do add a new rule in FxCop. i add a rule.. bt whn i chk runCodeAnalysis the following error message appear..
how to resolve this?
and i add exception like this in my xml code. bt error coms follows.

 <Exception Keyword="CA0001" Kind="Rule" TypeName="VariableNamingConvention" Category="Virtusa.Usage" CheckId="NR1001" Target="Virtusa.FxCop.NewDetector.VariableNamingConvention..ctor()">
      <StackTrace>
        at Virtusa.FxCop.NewDetector.VariableNamingConvention.Check(Member member) in C:\Documents and Settings\mcader\My Documents\Visual Studio 2005\Projects\Virtusa.FxCop.NewDetector\Virtusa.FxCop.NewDetector\FxCop\Rule\VariableNamingConvention.cs:line 20
      </StackTrace>
    </Exception>

this is the error message when i chk runCodeAnalysis ...


Error    2    CA0001 : Rule=Virtusa.Usage#NR1001, Target=Virtusa.FxCop.NewDetector.VariableNamingConvention..ctor() : Object reference not set to an instance of an object.    Virtusa.FxCop.NewDetector