Mac Pro won't start from DVD, crashes while trying

I have a Mac Pro 10.6.8 which will not start.

I wanted to re-install my Mac Pro (Intel dual core 2.66) which is currently running Mac OS X 10.6.8.

I inserted the retail Mac OS X 10.6 install disc, and held down the C key on my keyboard to boot the machine.

The disc can be heard spinning up, and the grey Apple logo appears. However, the Mac Pro crashes on start up from DVD, what can I do?