Dear Brian, thank you for taking the time to glance to my logs.
Feel really embarassed that I didn't noticed.
Problem solved and my old laptop begun upgrading.
Once again thank you, next time I'll be more careful ;-)
** Changed in: ubuntu-release-upgrader (Ubuntu)
Status: Incomplete => F
Public bug reported:
Unfortunately I am not in position to send any more information. I've
checked possible solutions (from uninstalling packages with hold status
to any other possible solution (e.g. unity and video driver uninstall))
with no luck.
Any further suggestion would be highly appreciat