Natural RPC server DB/2 error -805

I have a Natural RPC server running on MVS with DB/2 as a database. Any subprograms which get changed get bound to the db on moving between environments.
I can call the subprograms from a driver program but under the RPC server the same program returns this:

ST710N1 3420 NAT3700 Error -805 with SQLSTATE 51002 from call to DB2. Lib=ABSAST,Pgm=ST710N1,(NATURAL Error Info: Program=ST710N1,Error=3700,Line=3420,Status=O,Level=02)

According to IBM, this error could be a bind error.

Any help greatly appreciated on pointers to resolve it.


Natural RPC Server on MVS/ESA (NAT414)
Broker: Version Platform MVS/SP 7.0.6