If you has burnt some .iso-image with known md5-checksum, you can verify if disk is valid and was burnt properly
dd if=<your-CD/DVD-ROM-device> | md5sum
# dd if=/dev/hdc | md5sum && md5sum /mnt/win_e:/software/linux/systemrescuecd-x86-1.0.4.iso 68f9c2d885d95c82bfe6c7df736ae0a3 - <dd output skipped> 68f9c2d885d95c82bfe6c7df736ae0a3 /mnt/win_e:/software/linux/systemrescuecd-x86-1.0.4.iso
As you can see, md5sums are the same, so disk is valid. If someone knows how it could be done under MS Windows, please comment here.