Maybe some of you guys tried it? (Time Warner Cable NYC)

Right now I have an account with Time Warner Cable for digital cable and high speed internet (they call it their "The Best Package"). I only have two digital cable boxes in the house but would like two more. I don't want to "rent" more boxes from TWC. Considering that I will have to pay for cable tv for the rest of my life, I rather buy my own box. Eventually if this works I will replace all my "rented" boxes and buy my own, but of course I know you still have to subscribe to Digital Cable for them to work. I've tried =X

So before I go out and by a digital cable box, I borrowed one from a friend. The digital cable box is identical, is use for TWC in his home and is working 100 % (tested). Why doesn't this new box work in my house? Is it that TWC only sends signals to the two registered boxs that they originally gave me and I would have to call TWC and tell them that I have an extra third box in order for it to work?

I tried calling them and they sent a signal to turn it on and still no good. =( After troubleshooting for over 45 minutes, they finally asked to read the number off the back of the box to them. The number is on a sticker under the bar code, starts with a "PY". This leads me to belive that they only send signals to the "registered" boxes that they provide you with...I THINK. I've even tried using the new box in place of where my original boxes are. All my cable lines are working properly (checked and tested).

Can anyone help? Has anyone tried? Can anyone explain how this works?