Remember Microsoft has features to bypass its own Software Restriction Policies and AppLocker: Circumventing SRP and AppLocker, By Design and Circumventing SRP and AppLocker to Create a New Process, By Design.
Microsoft has issued a hotfix for this bypass: KB2532445
It is only for Windows 7 and Windows Server 2008 R2 though, it will not help you if you use SRP on Windows XP or Vist