RUNTIME_EXCEPTION NullPointerException: at com.sap.guid.GUID.parseHexGUID

I have just started testing an end to end process that uses RFC Lookups on PI 7.1 ...

when testing the mapping from the ESR in both message mapping and operational mapping, it works fine..

when i run it end to end i get the following error:

  <?xml version="1.0" encoding="UTF-8" standalone="yes" ?> 
- <!--  Request Message Mapping 
  --> 
- <SAP:Error xmlns:SAP="http://sap.com/xi/XI/Message/30" xmlns:SOAP="http://schemas.xmlsoap.org/soap/envelope/" SOAP:mustUnderstand="">
  <SAP:Category>Application</SAP:Category> 
  <SAP:Code area="MAPPING">RUNTIME_EXCEPTION</SAP:Code> 
  <SAP:P1>Thrown: java.lang.NullPointerException: at com.s</SAP:P1> 
  <SAP:P2>ap.guid.GUID.parseHexGUID(GUID.java:1015) at com.</SAP:P2> 
  <SAP:P3>sap.guid.GUIDGenerator.parseHexGUID(GUIDGenerator.</SAP:P3> 
  <SAP:P4>java:111) at com.sap.aii.utilxi.misc.api.GUIDFac~</SAP:P4> 
  <SAP:AdditionalText /> 
  <SAP:Stack>Runtime exception occurred during mapping</SAP:Stack> 
  <SAP:Retry>M</SAP:Retry> 
  </SAP:Error>

i can take the xml and run it perfectly in the ESR in both OM and MM mapping..... any suggestions? i believe all the config is there for the RFC Lookup...