After a lot of messing around and nearly hundreds of re-upgrades (little bit Exaggerating), I've finally found the perfect, secret formula.
So without further ado let's begin:
What you'll need
1) A Terminal - logged-in as root.
2) A Web browser open - just in case.
By opening-up a terminal > log-in as root (su, and then password) > copy paste this:
gedit /etc/apt/sources.list [enter]
You'll now see a text file displaying your repositories (see picture below), [what's commented with # means it's not in use] now change all the 'stable' / 'squeeze' words to 'testing' / 'wheezy' (without the quotation marks).
After changes have been made, save the file and exit. > back to the teminal - type / copy paste:
aptitude update [enter] aptitude full-upgrade [enter]
Aptitude will now check & maybe see that there is a dependency problem and will prompt you for a solution. As I said before - do not blindly trust aptitude (see aptitude for more info). >
Once you agree with the solution type ' y ' [enter] and the download will begin, > next you'll see a changelog - type :wq (including the colon, picture below).
> From time to time now you'll see a prompt message require you to O.K. it, it's O.K. to O.K. these messages but notice one message (pic below) that you'll need to use 'tab' button to 'yes' it.
Continue to the finish line.