Is that how it's supposed to work on X-Fi? The only EAX settings Audigy has apply system wide, so chosen preset is applied to any sound that is played by any program, which is not something you normally want (probably). Also, EAX doesn't work in Drakan if disabled in Riot Engine Options dialog or if you load a saved game made while EAX was disabled.
I also noticed in Half-Life 1.1.1.0, current EAX effect is apparently not stored in the save file, so if you load a save made while effect was active where you were standing, it won't be heard after load until you pass another trigger in the environment activating it. Like I said, old shit's bugged!