i don't have the 1804, but i do have the 1884 and it works within leopard without any problems. have you tried all fw port options? i know that some setups are inconsistent from one fw port to another. also with the 1884, there are in a sense two protocols at work: as an audio interface and as a control surface, so there are a few options within the 1884 software control panel to fiddle with if things aren't working correctly. sorry i can't be more help.