[Wine] Problem Installing Latest WINE in Backtrack 4

[RaistlinM531]

Hi all! 

A quick question: I just moved from Windows over to Linux, using Backtrack 4, which is based off of Ubuntu if I am not mistaken. One of the programs that I really need to get running, www.magicworkstation.com , really needs one of the later (unstable) releases of WINE to work. Well, so I go to follow the instructions to get the updated version, using the Ubuntu instructions and I get a little stuck. I go to 'software sources' then the 'third-party software' tap, where I am supposed to click on add and then copy and paste 'ppa:ubuntu-wine/ppa' into the field. I do that, but then the click-box 'add source' is greyed out, and will not let me add the ppa. 

Can anyone help me out? 
Thanks in advance -

RaistlinM