when i try to get the node of type "taskNode" from the process definition, some times it is returning tasknode and sometimes it is returning

"org.jbpm.graph.def.Node$$EnhancerByCGLIB$$52ac72a7".

Node futureNode = processdefinition.getNode("some task node name");

Usually everytime the above statement returns me only "tasknode"(because i am searching for tasknode only). some times it returns me "org.jbpm.graph.def.Node$$EnhancerByCGLIB$$52ac72a7", after exception during the process instance flow.

I am using jBPM 3.2.2

Could somebody explain me that why it is happening?