I did it!
I had this problem just a few minutes ago ... what it is ... okay ... maybe it's easier to show. Tell firebug to boot in a new window and it should go. If not, then read on and I will try to describe what is happening.
Do you see how the right kind had two panels? To the right is "quickview". What happened is that the panel somehow stretches all the way. If you hover over the left side of the panel, you can drag the panel back to the right. The separator between the panels is almost invisible when you drag it far in both directions, so you just need to make sure that you do not.
However, this is a great joke for other developers who don't notice this ... mwahahahaha.
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