I built a new PC that has a Diamond Radeon HD 6970 graphics card, and no on-board graphics. When I boot from the Ubuntu disc, it runs through some initial booting stuff, and then gets to a loading screen that just has the Ubuntu logo and some progress bar/dot thingies. After this screen is finished, it goes black and says it cannot display video mode.

I've seen many people that say to simply install the ati drivers. However, I don't believe this is an option, because I can't even get to the boot screen that asks me if I want to run the system off of the LiveCD, boot to hard disk, etc...

Is there a way to somehow boot to a CLI before getting to the screen that would normally let me choose that? I'm at a loss as far as what to do.

Also:

1. Yes, the CD boots fine on other machines. (I've also burnt a couple discs just to be sure)
2. Yes, the graphics card is fine. I normally dual-boot with Windows 7, and it runs on Windows just fine.

Thanks for any help!