For years and years, control-tab has been the key combination to switch to next tab. But not any more :-( With the trunk, hitting ctrl-tab now shows the very nice - but slow on old machines - tab preview dialog with genie efect. Fine with me if it still brings me to the next tab. But it does not ! I don't precisely understand what it does for the time being. Is it taking me to the next "unread" tab ? To the next in alphabetical order of the title ? I have no idea. There's only one thing I know : it's unusable because the result is unpredictable.  Dunno if it's a bug or it's on purpose. Please, ctrl-tab used to take me to next tab in tabbox and it should still do that. Just so you know, most average users probably don't know about ctrl-pageUp and ctrl-pageDown. Because it's alt-tab in windows to switch apps, they tried ctrl-tab in browsers. Conclusion : do not touch it.

Neil just told me on IRC it's supposed to be MRU, "Most Recently Used". Ah. Honestly, tastes more like "Magicly Repelling User-experience" to me... I did not get it at all. So what will the average user think ? If you have four tabs, two consecutive ctrl-tabs+release-keys-immediately makes firefox cycle between two tabs only since it goes to the most recently used... Impossible to understand for average users IMHO.

I think a change to a feature like ctrl-tab should not be so drastic. Second if really Firefox wants to offer a new user experience, it should be a pref turning on the new behaviour (and the corresponding UI in the prefs panel) but the old behaviour should remain the default.

jpb just told me on IRC that pref is browser.ctrlTab.mostRecentlyUsed... Just turn it to false to go back to normal (and predictable) behaviour. Already done here.