Standard & Poor's has reaffirmed Newtown's AAA bond rating, with a stable outlook.  The latest municipal audit also revealed positive results.  The Newtown Bee reports that while any cuts in state aid will put increased pressure on local municipal budgets, auditors determined that property taxes have provided a reliable revenue source.  Property taxes account for approximately 90 percent of the general fund revenue.  The Government Finance Officers Association has awarded Newtown its Certificate of Achievement for Excellence in Financial Reporting for the 17th consecutive year.