It takes ages to start the installation 10.5.1

i thought it might be a good idea to install zephirots 10.5.1 AMD release on my main machine as long as 10.5.2 isn't released to the public. At first i had to burn at least 5 DVDs at 2x speed until one of them worked. Now i am stuck at the Leopard wallpaper that appears before the setup should start. I am sitting here, staring at that wallpaper for over 15 minutes now and nothing happens. Same happened with the "information screen" when starting the installation. A few lines of text appear, sometimes it stops without an errormessage at searching the boot device, next time it goes a little further ... or not.

I tried several things. First i pulled off all my HDDs that shouldn't be involved into the installation (i.e. SATA HDD and 2 IDE HDDs). Then i tried to install it ... no luck, stuck at the information screen. I switched my HDD and DVD Rom from one IDE channel to another, tried it with every possible mix. Nothing ... i can't go further than to the wallpaper.

My rig is a premade Compaq Presario (AMD X2 4200) with an MSI Amethyst MoBo, everything were left original except the GFX-Card. I now have a XFI 8600 GT.

Uh .. wow ... after around 25 minutes the "Busy Ball" disappeared, now only the wallpaper is left. My DVD does nothing, same with the HDD -.-

Is someone around who could give me some advice?

,
Tom

P.S. I know i could wait until Zeph releases 10.5.2 but i am curious =)

//edit
Next try : This time it stops at "Still waiting for root device" and does nothing. Not even an restart