Access UDTF from MS SQL Server

I have created a User Defined Table Function (UDTF). When accessed from from iNavigator it works well. We want to access the UDTF from MS SQL using openquery but when we do we get the following message,

OLE DB provider "MSDASQL" for linked server "myServer" returned message "[IBM][iSeries Access ODBC Driver][DB2 UDB]SQL0551 - Not authorized to object myServicePgm in myLibr type *PGM.".
Msg 7399, Level 16, State 1, Line 1
The OLE DB provider "MSDASQL" for linked server "myServer" reported an error. The provider indicates that the user did not have the permission to perform the operation.
Msg 7320, Level 16, State 2, Line 1
Cannot execute the query "select * from table(myLibr.myUDTF('xxxx')) as t" against OLE DB provider "MSDASQL" for linked server "myServer".

The interesting thing is that it found the service program which is associated with the UDTF, myServicePgm, (although the error erroneously states that it is type *PGM instead of type *SRVPGM). The service program has *PUBLIC *USE authority so I cannot understand why this error message would be coming back.

Can anyone offer any insight?

Cheers,
Lorne.