When I launch Firefox 3.5.2 on my machines I have upgraded to Snow Leopard (I've tried 3 different machines), it doesn't show up on the foreground. I have to click the window (or tab to it) to make it foreground. This worked fine on 10.5.8, but under 10.6.0 it doesn't come up on top. Even if there are no other windows up, it still doesn't receive focus. And if there is other windows open, it shows up behind them.
same here.