Don`t panic!!! It`s a memory type thing. This link may well help you click here
If you think about DVD/CD burners, they suffered from buffer underrun at one time. Basically the data available, in this case, is less than needed to write to a disk. New DVD/CD burners have BURN (Buffer UnderRuN) protection.
In your case the buffer is being overfilled. You need more memory or need to free it up by closing some processes down. The former is the better solution.