OS 10.5 - Cant reinstall Tiger

Hi,

I got a problem:

Installed OS X 10.4
Installed OS X 10.5 update disk (because I bought Mac in okt. 2007)

Now I wanted to clean up everything and reinstall 10.4 and then the updatedisk.

But nomatter which cd i put in, when i restart the mac it won't install and just say:

'This sofware cannot be installed on this computer'

Now, i installed a downloaded version of 10.5 and everything is working (not illegal because i bought macbook WITH 10.4 and BOUGHT upgrade ).

Only thing is: the 10.4 came with ILife '08!
but now i cannot install it, because when i open the 10.4 disk, and open the "install bundled software only" , i get the same message:

'This sofware cannot be installed on this computer'



Anyone ANY Idea??? Please :/