I seem to be getting a 'disc is unreadable' error message every time I try to play Fallout 3. I saw a scratch on the first disc, so I bought another. The second disc I am having issues with as well. Sometimes, it's unreadable. When it does not say that, it lags very bad.

To resolve the lag issue, I tried installing it on my xBox. It only says that it's unreadable. The problem is that there are absolutely no scratches on my second disc, and it's not dirty. (It is pre-used, but it's in mint condition.)

I believe I have the latest patch, as well. Also, I bought Brotherhood of Steel expansion. This only started happening soon after I bought the expansion.

Also note that my xBox plays my other games with no lag or other problems.

Any help would be appreciated.