.net 4.0 A potentially dangerous Request.Form value was detected from the clientのソリューション

<?xml version="1.0"?>
<!--
         ASP.NET          ，   
  http://go.microsoft.com/fwlink/?LinkId=169433
  -->
<configuration>
<system.web>
<compilation debug="true" targetFramework="4.0"/>
<pages controlRenderingCompatibilityVersion="3.5" 
           validateRequest="false" clientIDMode="AutoID"/>
    <httpRuntime requestValidationMode="2.0" />
    <customErrors mode="Off"/>
  </system.web>
</configuration>