Here is a strange bug I'm experiencing in Firefox: I can only use either the chrome, or the content, not both at the same time!
For example, I can click on tabs and the toolbar icons, focus the search bar and write in it as well as the address bar, but if I try to click on anything in the content (eg a link or a textfield to write something), then nothing happens. The mouse pointer doesn't change either, it just stays a pointer when I hover over things, and the links I hover don't react either.
But if I alt-tab to another program (or click on it in the taskbar), then back to Firefox, then I can use the area that I click on. So if I click somewhere on the webpage to get focus back to Firefox, then I can click on links and write things (like this text), but I cannot click on tabs or refresh or anything else in the chrome. I can't even click on the minimize, restore and close icons! To get focus back on the chrome I have to alt-tab to another program, and then click on the chrome to get back to Firefox to be able to use the chrome again.
I've tried closing and starting it again, but the bug is still there. I have experienced this before, but I don't remember what I did to fix it. This bug seems to occur sometimes when I wake up the computer from standby, but I leave by computer in standby all the time, so that is not the only factor.