Buffer Under-run (BURN) Errors occur when the computer cannot supply a steady stream of data to the CD Burner, which is required for CD burning. The CD Burner has a memory buffer that is designed to prevent the drive from "running out" of data when the computer cannot supply it fast enough, but if the computer "slow down" is long enough the buffer in the CD drive will run out and cause the disk burn to fail. The buffer is said to have "under-run" when it is out of data.