Thanks Jamie. I do have my filters defined and for testing, I have hard coded the values. There's a few more info I should have added.
1. I have the same application using the same code for another service which works fine. Since the query is essentially the same, I just needed to change the URL to point to the right service and the correct sPath
2. We are going through SMP 2.3 to get to Gateway so the alias or the end point is: http://mydomain:port/com.my.applicationID
3. I used RESTcClient to test the end point directly to GW and it is fine. I don't think this is an SMP issue, but I'm not sure.
Thanks for the reply