On my iMac 1Ghz 512ram, Firebird 0.7 (and Mozilla 1.5), is much slower than Safari, including the window scroll speed (Safari is just one snappy S.O.B.). I attempted to install themes, but after saying the theme was intalled successfully, it would not show up under Themes in Preferences, even after restart. When installing themes manually from a .jar file using the theme installer extension, the Program crashed every time. I know many people boast about the product deserving alot of praise, but from what I've experienced on my Mac, I am better off sticking with Safari for all general browsing, and Internet Explorer (!!!) for the tougher Java stuff, some of which Safari is still very weak at. On the surface, Mozilla seems like a bloated beast, although with much promise.