Why wont my 10.5.4v disc install on my Mac OS X version 10.4.11....??

If that is not a full retail disk, but an install disk from another Mac, it will not work. Install disks are machine specific. Can you post a screenshot of the disk so we can have a look? If it is grey, it's a machine specific disk.

Because you can not use the system disc from another Mac. To upgrade your Mac to 10.5, you must use a Retail Leopard or Snow Leopard Upgrade Disc.

You'll need a Leopard retail install disk.

This info is provided by TexasMacMan, with updates from me;

Mac OS X 10.5 Leopard installation system requirements

http://support.apple.com/kb/TA24950

Leopard is no longer available at the Apple Store but may be available by calling Apple Phone Sales @ 1-800-MY-APPLE (1-800-692-7753). {Note - this is now very unlikely, but no harm in asking}.

If you can't obtain a retail install DVD from Apple, look on Amazon MP, eBay or Google the installer part numbers to possibly find at an on-line store. Here's what to look for:

MB427Z/A Leopard 10.5.1 install DVD

MB576Z/A Leopard 10.5.4 install DVD

MB021Z/A , MC094Z/A Leopard 10.5.6 install DVD (single user)

MB022Z/A , MC095Z/A Leopard 10.5.6 install DVD (5-user family pack)

{the bold order numbers are the later ones}

Installing Mac OS X 10.5 Leopard

http://support.apple.com/kb/HT1544

Mac OS X 10.5 Leopard Installation and Setup Guide

http://manuals.info.apple.com/en/leopard_install-setup.pdf

After you install the base 10.5, download & install the 10.5.8 combo update at http://support.apple.com/downloads/Mac_OS_X_10_5_8_Combo_Update

{This is still available on Support Downloads}

Very good information. Just wanted to add that I confirmed 12/2012 that Apple no longer sells OS X Leopard 10.5 via phone sales. They only have Snow Leopard now.