Maybe you have to un-pair it first with the other two computers.
http://www.google.com/cse?cx=011016...e:forums.macrumors.com&hl=en&as_qdr=all&meta=
The thread title guy strikes again:
A more descriptive and precise thread title will help cater to the right audience and get you more responses.
To edit your thread title, just click on the
button on the bottom right of your original post and then click the "Go Advanced" button below your message.
Have you also taken a look at MRoogle, since that question may have been asked several times?