installation failure

This problem may appear when:
1) the DVD is corrupt => check MD5sum (you did it so it is not your case)
2) the DVD drive or controller is not supported by the kernel

Unfortunatelly, you cannot easily change the support of your hardware by the kernel, but you can change its boot options.
From the boot menu of the DVD, add (=type) these additionnal parameters to the boot line:
all-generic-ide irqpoll

Depending on your hardware, it may solve this issue.

Good luck

PS: a new release with a more recent kernel will be released in approx one week from now