te37v, it asks you to do it via the suite because you do not have enough rootfs space free.

It needs somewhere between 70-83mb (people have reported the odd variants).

If you are confident enough in the backup / restore process, and you know how to save key files (debs etc) then my recommendations are:

1) Ensure you have a backup (Back the backup to a pc just incase)
2) Remove all non-essential apps, games etc....
3) in terminal type df-h (It will tell you your root free space)
4) if you still need more space, disable all repo's that are not needed
5) remove more apps/games etc if you can
6) run apt-get clean and apt-get autoclean in terminal as root
7) reboot
7) check space again...
8) If you still need more space then you can hunt these forums on how to symlink files (i moved a folder with some help that saved me 15+mb)
9) once upgraded, restore your apps from the original back up! tadaaaaaaaa


If you have concerns with any of the above, i'd recommend using pc suite