Been using FF3 for a day now and the only bug I can see at the moment is when your organising your bookmarks, Alt+B then Ctrl+Shift+B. In the top left corner where you should have the forward and reverse buttons? They're not displayed properly.
And I can't seem to organise my bookmarks in name order.
So I might have to revert back to FF2 as it seems that FF3 is buggy, as to be expected.
We'll see how it goes for the next few days.