Sounds like the image was corrupted when being burnt to cd, or the cd is rubbish quality.

Use a quality brand cd and burn at x1 speed only, and make sure there are no smudges or scratches on the disc surface.

I use ultraiso for the burning and I have had no problems.

Also you might want to try v28.

There is a procedure for ejecting the disc somewhere, try a search.

Hope this helps.