Blank screens, steam overlay failing, unresponsive screens

[Poot]

Everything except for the Library tab is a blank page. If I mouse over the blank page, the mouse icon will change as if it knows it's hovering over a link or text, but I see nothing. Refreshing does not help.

Also, when I try to trade over steam, it often does the same thing. Usually if I cancel and re-initiate the trade, it corrects itself, but sometimes it can take multiple tries.

Is this a known issue? I'm using Lion and steam is up to date.