[syslog-ng] Question regarding filters

I don't want to assume anything about how the program deals with messages, so my question is how do messages that match or do not match a filter cascade down? For instance if I have a filter: filter f_test { program('test'); }; and a destination that specific filter, under what conditions would it NOT make it to said destination? What's going on is I log output from a program, but it's making it's way into /var/log/messages, when it should be going to it's own definition /var/log/services/app/app.log. Does the order of log { } make a difference? filters? destinations? I looked around the faq and the reference manual and didn't find anything explaining the process flow. Thanks in advance! Ian