can't locate array.contains in VS2010 ( VB.NET )

hello,

 the following logic ( specifically arrExceptions.Contains(ch)) works fine in VS2008, but not in VS2010, may be i am missing an imports or something ...

   Private Function strFilterExceptions(ByVal strToken As String, ByVal arrExceptions() As Char) As String

      strFilterExceptions = ""

      For Each ch As Char In strToken
         If Not arrExceptions.Contains(ch) Then
            strFilterExceptions += ch
         End If
      Next

      Return strFilterExceptions