When using the View > Toolbars > Navigation Toolbar option in the (global) menu, the bug appears (as described in the first post). But when I right-click on a toolbar, and then select Navigation Toolbar (i.e. not with the global menu) to do exactly the same thing, the bug doesn't appear.
But as I wrote above, this is certainly not the only way to trigger the bug. I'll try to find another reproducable way to trigger it.
By the way: using Firefox and Thunderbird 15 on KDE 4.9.00, Kubuntu 12.04.
This is strange.
When using the View > Toolbars > Navigation Toolbar option in the (global) menu, the bug appears (as described in the first post). But when I right-click on a toolbar, and then select Navigation Toolbar (i.e. not with the global menu) to do exactly the same thing, the bug doesn't appear.
But as I wrote above, this is certainly not the only way to trigger the bug. I'll try to find another reproducable way to trigger it.
By the way: using Firefox and Thunderbird 15 on KDE 4.9.00, Kubuntu 12.04.