Firewire Disk Mode Snow Leopard Installation not Working

HI All

New to this site.

I have been googling this a lot in the last couple of days to try and find a solution to the problem. I can summarise the problem as:

1. I have a new macbook pro with lion.

2. i have an old macbook pro with snow leopard, but with an optical drive that no longer works.

3. i want to do a clean install of snow leopard on the OLD MAC with the dodgy optical drive, to wipe all the apps etc. to give to a friend.

4. I have been trying this by putting the installation disc in my new macbook pro, then restarting it in firewire target disc mode. That works fine and as expected.

5. once in target mode, i connect the new mac to the old mac via firewire and switch on the old mac and hold the option key and then select the DVD drive of the new mac to begin booting from that disc.

This is where it starts to go wrong i think.

In all the forums i have read, after step 5 everyone says the installation begins as usual and everything is fine.

On mine, you can here the dvd drive on the new mac being accessed. On the old mac, the screen is grey with the apple logo showing. After a few minutes the dvd drive seems to stop being accessed and in addition to the apple logo showing on the old mac, the grey booting up wheel now shows..

At this stage the wheel and apple logo appear indefinitely and nothing seems to happen.

Does anyone have a clue why this is?

Many thanks in advance!!!