Strange behaviour in Firefox 15

[silverback]

On Options | Tabs in Firefox 15 I have "Warn me when closing multiple tabs" set - as I have had for all previous versions.
However, since installing v15, Firefox is closing multiple tabs immediately with no warning. Anyone else noticed this?

Silverback

[Leif]

It's working OK for me:

x.jpg

Incidentally, I don't normally have that option selected, but for this test I had ALL options on the Tabs tab selected.

[silverback]

It's working OK for me:

Aha - I have the solution! You suggestion didn't work for me so I Googled for the problem and, if the option "Always use private browsing mode" is set, then Firefox closes immediately, regardless of any tab settings.
Now - how that option got set is the next investigation!

Thanks
Silverback

[Leif]

Thanks for posting back!