[X4U] 10.5 instead of 10.6

[Paul Moortgat]

On a new Mac Pro one need 10.5 instead of 10.6.  I called Apple  
because 10.5 would not install.  They told me that was because 10.6  
was already installed.
I argued that I started with a DVD.  The mac will see the 10.5 and  
will not proceed was the answer.  I removed the drive with 10.6 and it  
still didn't worked.
Can that 10.5 DVD be damaged while I can use it on a Powerbook?  The  
10.5 is a retail version I bought for 160 euro from Apple.
One need Appletalk for printers and it's not on 10.6.

Paul Moortgat