Comment 7 for bug 522727

For a few days now, I'm having the exact same bug - even with addons disabled.
I am running Firefox in safe-mode right now, with my tabs still not-clickable. (Firefox 3.6 (not 3.6.2), on amd64, karmic and linux-kernel 2.6.31-19)

Kris' steps to reproduce the bug work - although it occurred to me in other cases at first.
I supposed that middle-clicking might be of key-importance here, but right-clicking and hitting "Open Link in New Tab" does the trick as well.