I am not using Firefox now but using Safari 5.0 as I had not had problems with Safari, but of course it could be a browser thing?
Not a big deal, really, I just thought I would point it out as others may try to use the site in the same way as me, which may not be how you intended but is intuitive to me.
If I want to move the contents of a page around and click on Start Builder, I usually just close the pop-up window because it is in the way. But sometimes I want to edit the content of a box at that point, and if I click on the "Edit Box Content" icon at top right of a box, it does not work, (it does not open the pop-up window to display that boxes content for editing) - most of the time I think. I have experienced this over and over and I thought it sometimes did and other times did not, but when I just went to test it out so as to be clear here, it seems it consistently did not open.
I understand that I closed the pop-up window, it is just that the button is right there, and all other visible functions work, so it seems odd that this one does not when clicked. I suppose it would be a convenient way to re-open the pop-up window rather than having to Stop Builder and then Start Builder again.
As I said, far from a big deal, just wanted to share it as feedback for when you have time for less important improvement considerations.
button — it currently closes it for good. This is a default behavior derived from our ajax popup windowing; I should add in a reactivation setup there, as this is indeed a bit confusing. In the meantime, just minimize 
instead. (You can also do it by double clicking on the top bar of the builder box.)
