[syslog-ng] Problem with hostnames (keep_hostname(no);)

Hiya folks, Here's the situation: All devices log to syslog-ng Syslog-ng then forwards logs to individual NMS systems, like Ciscoworks, etc. We're setting up a demo of Loglogic and are forwarding from the NG server to Loglogic. I'm getting the messages on the Loglogic side, but the originating hostnames are coming in as the NG server, not the actual device names (so it only sees one source) I've tried setting keep_hostname(no); but this doesn't seem to correct the problem. Any suggestions? TIA! Clayton