Not logging in as root after upgrade

[Machia]

I have Kali 1.0.9 installed on my HDD and, after an upgrade, it has now decided it doesn't want to log me in. I have tried my usual password and toor, unfortunately to no avail.

I have been having a number of issues lately - deletion of Network Manager, for instance - which I have been able to solve. I now hit a brick wall, however, as I cannot see a way around solving this. Any help would be greatly appreciated!

[g0tmi1k]

Has your keyboard layout changed?

Else, you can reset the root password, http://www.debianadmin.com/how-to-re...-password.html

[Machia]

Has your keyboard layout changed?

Else, you can reset the root password, http://www.debianadmin.com/how-to-re...-password.html

Just checked - the keyboard layout hasn't changed.
Aside, the laptop is running markedly slow, refuses to remotely reboot from login and the screen turns off after about 5 seconds.

I followed your link and now I'm just getting a black screen with a 'command prompt insert' in the upper right corner. It may just be running even slower, but it's still not meant to take this long (it's been a few minutes).

Edit: I tried rebooting again and it got past the black screen this time. However, the password to which I reset it from your link hasn't stuck