@jonspeegle:
I can't find anything that explains why this is not working. I'm going to setup a test lab to see if I can duplicate. Could there possible be a bug with the snort implementation in pfsense?
I'm not going to say that is impossible, but it would have to be assumed as unlikely since other rules are firing for you. If I understood you correctly, once you fixed the HOME_NET issue, you have only that single rule that is not firing the same on both sensors.
If it is a bug, it could be in either place (the DMZ sensor may be incorrectly triggering, or the pfSense sensor my be incorrectly missing it). Does the other sensor use libcap? I know that's what Snort is using on pfSense.
Bill