I'm having terrible problems with the bookmarks toolbar. If there's folders inside the folder it's impossible to navigate to the last level, which means that I can't reach most of my bookmarks. It happens in places to with the starred lists.
It's like it loses focus on where the mouse pointer is and jumps to another submenu.. kind of hard to explain, but it makes Firefox unusable for me until that bug is fixed. The cursor itself even changes (seemingly randomly over these menus) between text input, arrow and hand.
I'd even decided to try it with a totally clean install of Leopard, the only change was to set mighty mouse to a 2 button, and the only program added was Minefield (the Firefox 3 beta).. same thing happened. I'd even made sure to remove any peripherals for the install (before installing Leopard) so I know it wasn't my Wacom tablet, external drive or printer. Other than the RAM, this iMac was set back to factory default with a totally clean OS.
I tried it on my Tiger clone to, happens there as well.
Very frustrating! I love Firefox and can't narrow down why this is happening

(There isn't any consistent errors in either OS X's console.log or Firefox's error console)
Anyone else have this problem?