-25507 error

We have a Sun server, Solaris 2.6 on which I installed CLIENT SDK 2.x. The database that we want to connect to is on another server, HP-UX 10.20 running IDS 7.31.UC4. We modified the sqlhosts file and /etc/services on the Sun server. Informatica is the application which is running on the Sun server. When it tries to connect to the HP server, it gets a -25507 error: You specified an unknown service name or protocol. Tell your database administrator to examine the sqlhosts file entry. Check that the NETTYPE settings in the ONCONFIG file match the NETTYPE settings in the sqlhosts file. If you are using the TCP/IP protocol, check that the correct service name appears in the /etc/services file. If you are using NFS, use ypmake to check the /etc/services file. Sometimes the daemon does not recognize service names that are added after a default boot. I know that the sqlhosts and /etc/services entries are correct. The database server has been around for years and other servers with different applications use the same settings to connect to the database. Ypcat is not used. Does anyone have any ideas on what else could be the problem. Thanks, Dianne