I have some DVI cable questions!

First off, let me say I'm not much up on DVI cables so if I say the wrong thing please forgive me. Here's the deal:

When I installed my projector I went ahead and ran a DVI cable. However I used whichever DVI cable the 990's connector does NOT have...I have the DVI with all the pins and the 4 little extra pins (I think my cable is DVI and Analog) and of course the Outlaw does not have the 4 extra pins and my cable does not plug into it.

I guess the question is...do I need these 4 pins for anything? Can I just break them off so I can use the DVI cable with the 990? I hesitate to break them in case they need to be there in the future for something. If I were to plug a laptop with DVI output into it would I then need the 4 pins?

Here's what I'm trying to do in case you're curious...now that the Xbox 360 has the killer HD-DVD drive I'm wanting to get the VGA adapter for it and plug it into the DVI input using a VGA-DVI adapter...is there any reason why this shouldn't work? Thanks!