Sometimes, when I press ctrl+t, I get the tab in my tab bar, but it is not functional(clicking it does nothing, and ctrl+pgup/dwn will show the previous tab for a few presses until it gets passed the broken tab), and the only way to close Firefox afterwards is through the menu, pressing the 'x' in the corner will do nothing. I would say this happens about 50% of the time. If I use the plus(+) at the top to open a new tab it always works. I have been having this problem for atleast the past 5 versions, or more. I have tried with a new profile, and no addons loaded, and it still happens. Is this just my computer?