One problem i had several times, is the fact opera remembers just the tabs opened on the last window.
I have 30 tabs opened, i open a new window for "x" reason, and on this new window just 3 tabs.
i suddenly need to restar or whatever, i close first the window with 30 tabs, then the windo with 3 tabs, and after reboot, i open opera and surprise, the 30 interesting tabs i had... gone, all i get is the 3 tabs i had in the last opera window.
thats bad!! please implement some type of function to save all the tabs somehow, it husrt lose some information just becuase i close the opera windows in the wrong order,