How long did it take to finish the update and self-reboot on an N800 ?

I did the update on my N810 and no problem, all went fine. But on my N800 the update seemed fine, the blue progress bar finished and a little "Updating" square popped-up on the upper right corner of the screen. The "Updating" square has been there with its "rotating dot animation" (if you know what I mean) for about 10 minutes and nothing happens....

Shall I just interrupt this ? and reboot the machine? wait (till battery drains) ? ..... I have no weird things like rotate screen or things that made the previous SSU's sort of crash...

Your comments are appreciated, TIA.