AS400 Toolbox problems - ServiceProgramCall

Has anyone successfully managed to call a procedure in a service program,
using the ServiceProgramCall class? 

I'm having major problems getting this to work:

Passing by reference doesn't work at all - get null pointer errors in the
procedure.

Passing by value works for integers, but Strings get garbled. I thought this
might be a CCSID problem, but the same code works fine for a ProgramCall.

Does anyone have any working examples using this class, there aren't any
that I can find in the toolbox documentation.

Confused, 
Chris.




=======DISCLAIMER=======
This email transmission and any attachments may contain confidential
information which is legally privileged.  You are also notified that the
contents of this email and any which you may send in reply, may be viewed by
authorised personnel on behalf of NSB Retail Systems Plc or its subsidiaries
(the Company) in accordance with the Company's Information Access Policy.
The content of this email is always subject to contract.  The information is
intended only for the individual or entities to whom it is addressed.  If
you are not an intended recipient please contact me immediately and you are
hereby notified that any disclosure, copying, distribution, storage on any
medium or use of the information contained in this transmission is strictly
prohibited.

+---
| This is the JAVA/400 Mailing List!
| To submit a new message, send your mail to JAVA400-L@midrange.com.
| To subscribe to this list send email to JAVA400-L-SUB@midrange.com.
| To unsubscribe from this list send email to JAVA400-L-UNSUB@midrange.com.
| Questions should be directed to the list owner: joe@zappie.net
+---