NPE getting raw request from REST Request step

I capture the raw request from a REST request in a Groovy script like so:

def rawReq = new String(testRunner.testCase.testSteps['RESTRequestName'].testRequest.response.rawRequestData)

When I run the script in the Groovy step editor it works, but when I run the test case, the script fails. I see an NPE in the error log:

Wed Mar 10 10:26:15 EST 2010:ERROR:java.lang.NullPointerException
   java.lang.NullPointerException
    at java.lang.String.<init>(Unknown Source)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at org.codehaus.groovy.reflection.CachedConstructor.invoke(CachedConstructor.java:77)
    at org.codehaus.groovy.runtime.callsite.ConstructorSite$ConstructorSiteNoUnwrapNoCoerce.callConstructor(ConstructorSite.java:107)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallConstructor(CallSiteArray.java:52)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor(AbstractCallSite.java:192)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor(AbstractCallSite.java:200)
    at Script1.run(Script1.groovy:3)
    at com.eviware.soapui.support.scripting.groovy.SoapUIGroovyScriptEngine.run(SoapUIGroovyScriptEngine.java:93)
    at com.eviware.soapui.support.scripting.groovy.SoapUIProGroovyScriptEngineFactory$SoapUIProGroovyScriptEngine.run(SourceFile:51)
    at com.eviware.soapui.impl.wsdl.teststeps.WsdlGroovyScriptTestStep.run(WsdlGroovyScriptTestStep.java:148)
    at com.eviware.soapui.impl.wsdl.testcase.WsdlTestCaseRunner.runTestStep(WsdlTestCaseRunner.java:194)
    at com.eviware.soapui.impl.wsdl.testcase.WsdlTestCaseRunner.internalRun(WsdlTestCaseRunner.java:125)
    at com.eviware.soapui.impl.wsdl.testcase.WsdlTestCaseRunner.internalRun(WsdlTestCaseRunner.java:39)
    at com.eviware.soapui.impl.wsdl.support.AbstractTestRunner.run(AbstractTestRunner.java:138)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

This was working fine in earlier versions (though I am not sure when it was broken as I have not executed this test case for a few days.)

This is blocking issue for me.