Inconsistent stack height when using super inside a conditional

When having a class like this:
************************************************************************************************
public class RedirectOperation extends XMLOperation
{
protected void _processXML(
StreamSource xmlSource,
XMLOperationDescriptor theXMLOperationDescriptor,
HttpServletRequest request,
HttpServletResponse response,
ServletContext theContext,
Hashtable theParameters,
Hashtable theEnvironment)
throws TransformerException, IOException, OperationException
{
def doc = new XmlParser().parse(xmlSource.getInputStream())
xmlSource.getInputStream().reset()
def redirectURL = doc.REDIRECT_URL.'@Url'
if(redirectURL[0])

else

}
}
************************************************************************************************
Class is compiled and the .class file used. Executing the method on an instance raises this error:
java.lang.VerifyError: (class: es/uib/test/RedirectOperation, method: _processXML
signature:
(Ljavax/xml/transform/stream/StreamSource;Lorg/leaf/XMLOperationDescriptor;Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;Ljavax/servlet/ServletContext;Ljava/util/Hashtable;Ljava/util/Hashtable;)V)
Inconsistent stack height 1 != 0
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
...

If, for example, one removes the "else" clause and places a return at the end of the if clause, then everything works as expected.

Verified with Groovy 1.0 and Groovy 1.1b2
Groovy script compiled through the Eclipse plugin

S!