|Try a different brand of blank discs.|
"if it tries and fails, is the cd trash?"
It depends on the nature of the write failure. If even a small amount of data has been written to the disc, it can't be used again.
Your burning software should tell you. If you try to burn to a disc which already contains data, It will say something like "the disc is not empty" or "please insert a blank disc"
Moreover, you can usually tell if you look at the data surface of the disc. If it's got dark bands on it, it already contains data and can't be used for burning more data.
message edited by phil22