This is just a longshot, but try burning a file that won't work to cd, then try running it from the cd. If that doesn't work, try playing it from the cd on a different computer. If it works on the other pc, you'll know it's your pc with the problem, but if it doesn't work then it might be the files that are corrupted or something.

Or, if you can be buggered, you could try reformatting again.