Can not assign Privileges for procedures in HANA trial

Hi,

I am using the HANA trial version. In an xsjs file a procedure is called like

var cst = conn.prepareCall( "call mC_get" );

The procedure is located under my NEO-xx schema in procedures and reads from a table of that schema.

The table select priviliges have been assigned and  native select statements work from xsjs .

The call procedure  statement however  throws an error like

"Error while executing query: [dberror(Connection.prepareCall): 258 - insufficient privilege: Not authorized at ptime/query/checker/query_check.cc:2182"

I was trying all kind of sql grant statemants to grant some select privileges but did not succeed (mostly the grant statemebnt throwed another insufficient privilege error)

What do I need to do to allow the xsjs app process my stored procedures ?