REGRESSION:No longer able to set the classloader

J2SE Version (please include all output from java -version flag):
  java version "1.7.0_25"
  Java(TM) SE Runtime Environment (build 1.7.0_25-b11)
  Java HotSpot(TM) 64-Bit Server VM (build 23.25-b01, mixed mode, sharing)

Does this problem occur on J2SE 6ux or 7ux? Yes / No (pick one)
   Unique to update 1.7.0_25 b11

Operating System Configuration Information (be specific):
   Windows 7 Ultimate 64 bit SP-1

Bug Description:

We have a place in our application where we can run a groovy script to make custom manipulations. However, now with 7u25 b11, the class loader cannot be set. We have our application signed with all permissions and it is launched through webstart. We are currently using groovy 1.7.0 still, but we could upgrade it if that would help.

I know there has been a big push for security recently, but this seems a bit heavy-handed and doesn't leave me a lot of options.

(We actually extend the GroovyClassLoader so we can restrict what classes are accessible to our script, but I don't think that matters to this discussion.)

---- (1) ---- Throwable - Class (class java.security.AccessControlException)
    Message (access denied ("java.lang.RuntimePermission" "getClassLoader"))
    at java.security.AccessControlContext.checkPermission(Unknown Source)
    at java.security.AccessController.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkPermission(Unknown Source)
    at java.lang.ClassLoader.checkClassLoaderPermission(Unknown Source)
    at java.lang.Thread.getContextClassLoader(Unknown Source)
    at org.codehaus.groovy.control.ProcessingUnit.setClassLoader(ProcessingUnit.java:101)
    at org.codehaus.groovy.control.ProcessingUnit.<init>(ProcessingUnit.java:64)
    at org.codehaus.groovy.control.CompilationUnit.<init>(CompilationUnit.java:132)
    at org.codehaus.groovy.control.CompilationUnit.<init>(CompilationUnit.java:112)
    at groovy.lang.GroovyClassLoader.createCompilationUnit(GroovyClassLoader.java:456)
    ...