Stored procedure call not working

I have a defined a stored procedure using a service program

CREATE PROCEDURE DEVIILIB/TESTITRANSFER(IN ID_NUMBER BIGINT )
LANGUAGE RPGLE
NOT DETERMINISTIC
NO SQL
EXTERNAL NAME 'DEVIILIB/ITTEST(TESTPROCEDURE)'
PARAMETER STYLE GENERAL

I went to IBM Redbooks and this is exactly the way they show it being done
and using Ops Nav to test.

I can call this stored procedure through an RPG program without a hitch but
when I try to call from Ops Nav or from a C# program it fails with a
message saying

Program ITTEST in library DEVIILIB not found. Obviously the service program
is there because I works through RPG

CALL DEVIILIB.TESTITRANSFER(1)

from Ops Nav.

I know it is seeing the stored procedure definition because it says it
can't find the program or service program.

I have checked the service program and the public has change authority
which includes execute.

Have I got an IBM bug of some kind? I have used stored procedures
implemented with service programs for years.

Any ideas?