Screen gibberish on fresh install

[stanton warrior]

I'm having problems installing 11.10 64 desktop on this machine:

Asus M2N-SLI mobo
AMD Athlon 64 x2 dual core 4200+ CPU
MSI R6670 graphics card (Radeon)
Western Digital 250Gb and 500Gb hard drives

I have installed Ubuntu successfully on this machine in the past (up to 10.10) without hassle. However, I was previously using an Nvidia card.

I have since changed to the above Radeon card and whenever I try to install either Ubuntu or Mint, the splash screen is OK and so are the initial "casper" text commands.

And then I get a screen like this:

http://i46.tinypic.com/wh2lh.jpg

I presume it's a driver issue? I had thought that it may have been something to do with the previous installation having Nvidia drivers but I've wiped that partition and am still getting the same problem. The card works absolutely fine in *******.

I'm still very much a noob when it comes to troubleshooting Linux problems, so I hope somebody can help. I've tried searching for solutions and have tried installing KDE versions (such as Mint's KDE version) but still get the same problems.

Can anybody help? Thanks.

[AbeFM]

Can help other than to say I saw it too. Nvidia. I rebooted a bunch of times, with "safe mode" and all those variations. One time I happened to get a visible screen, and installed the nvidia drivers. Now it works, but it's several minutes' wait every single time something uses transparency. UTTERLY unusable. A few hours of messing around and I'm going back to windows.