If your CD/DVD drive is still spinning at this point and the light is working, than chances are you are perfectly fine, nothing to worry about. But unfortunately with this particular distribution of OSX86, there are some issues with older hardware. You will need to go through a lengthy process in order to get back on the right track to install Leopard. From what I've seen the problem mostly involves NVidia chipsets, but it could be other hardware that causes its malfunction as well. Here is the website that has the patch, you may be able to find instructions as to how it is used as well. (It involves messing with the .iso file that you downloaded earlier, and you will need some basic knowledge of the Windows command line or Linux Terminal)

The Patch website : click here

Remember when i said in the materials needed section that you may need 2 blank DVD-R's? It's because if you have this problem you will need to burn the patched .iso to a new disk in order to use it.

Here is a screen that might tip you off that you have a problem:

The link shown above is part of the iDeneb website. If you have further problems with this particular distro, consult that website and the forums at InsanelyMac.

(Also, when first booting the DVD at the part where it prompts with "press any key..." press F8 and then -v in order to boot in diagnostic mode. This may be useful for troubleshooting)

This is the screen (in diagnostic mode) where the failure usually occurs:

Back to the ideal installation case, these failures are depressing!

A gray screen will load with a cursor or colorful pinwheel in the upper left corner. Then a Blue iDeneb screen will appear:

Then the language selection screen will appear (English for this tutorial):

Loading Screen: