Installing OS X 10.6 fail

I'm trying to install OS X 10.6 on my MacBook Pro 2,2 2.16 Ghz.

Now running 10.4.11

Install disk is CPU Drop-in DVD 10.6 (2z691-6431-A)

Specs:

MacBook Pro 2,2 15",

Intel Core 2 Duo,

2Gb Ram (2xDDR2 SDRAM 667MHz),

Bus speed 667 MHz,

320 Gb HDD 7200 rpm,

Boot ROM: MBP22.00A5.B07,

SMC Version: 1.12f5,

For some reason my build-in speakers diappeared from my system setup, so I have decided to make a clean install from OS X 10.4.11 to 10.6, all my data have been transfered to an external harddrive and I'm ready to erase/format my internal harddrive.

When I'm trying to boot from install disk, I'm asked to choose language, then it starts to prepare the installation, but a pop-up says that I need to have 10.5 or later installed to install 10.6 and I can only choose to "Restart" or "Repair Disk"

Question: Is there a problem between my hardware and the 10.6 installation disk?

Can I resolve this?

Any ideas ??