Vanishing Files? NOT A NEWBIE

Hi

I have successfully burnt around 20 dc games but i have suddenly come accross a problem. When i download Utopia needed games and putting them on cd. The Burn goes perfectly alright and you can see what it's burnt by looking at the back of the cd but the game dosn't work and i cant see whats on the cd with my computer.

Can u please help me asap cus i am getting a LARGE collection of expensive coasters.

Thanks in Advance

Steve