Also, sometimes the BF2/FH2 server browser just decides not to work correctly. Hell, I think I've seen the entire GameSPY server disappear at least once.
If nothing else works, you might just have to wait a while for the server browser to kick itself in the ass and get itself working again.
In other words, if you have the right files, have the filters set correctly, and have BF2 patched up correctly, the problem might simply be with EA's server browser thingy. But make sure everything's right on your end first.