Can't install OS 10.5 Leopard disk image

I downloaded OS 10.5 Leopard disk image, burnt the DVD, put it in to install but got the message "cannot install software on this computer". I'm trying to install it on my Macbook 2 GHz Intel Core 2 with OS 10.4.11. Is it because this disk image is assigned to a specific machine? or is my computer not got enough balls? Any tips on how to get around this? Thanks to all who help - may internet karma shower upon thee.

m. aurelius