I had the same problem - go to TOOLS - OPTIONS - TABS - and check Warn me when closing multiple tabs!
Oh... and only the first tab is BrainDen, I have one Firefox start page, FB, and four dictionaries plus a chemistry tab!
ON TOPIC: I hate know-it-all doctors <_< I went to a neuropsychiatrist (work related) and she kept pushing my buttons (and she banged me with her hammer couple of times too) anywho... she kept dancing on my nerves and I was anxious to finish all my doctor appointments till one a clock, but nooooo, she had to be difficult so I reacted and get this... she actually wrote on the paper anxious-reactive!!! I couldn't believe it... she pushed me over the edge and then wrote that I was anxious-reactive!!! Well she got nervous towards the end too, but she didn't write that down... did she?? <_<
I went again today and finally got my work related permit... <_< but the anxious-reactive sentence is still there... black on blue! <_<