Great to see that the latest update to Firebug has fixed the issue that I reported about it breaking when you opened Firebug in a new window (see Firebug bug at the other place).
Next up, I hope that the alignment of menu items gets fixed in the next update to the Web Developer add-in … it’s just annoying!
Here’s an example (above). You can clearly see that the icons aren’t equally aligned on the left.