BIG problem after installing Leopard

So I got an iMac 20 inch 2.16ghz Core 2 Duo that originally had 10.4.7 on it. I didnt upgrade to 10.4.11. I installed Leopard(I didnt choose the upgrade option), and during the final phase of the install it stuck on "one minute remaining" for about 30 minutes.

Then once Leopard was installed the screen had weird pixels in it fulbs and som e horizontal lines my mouse went over and started freezing.

So I am doing a total HD clean and reinstall of Tiger. During the install I see none of the lines on the screen I saw on the Leopard desktop.

Does anyone know why this happened when I put on Leopard?

Is the disc a full retail install and not from another machine, and did you run Repair Disc and reformat?

A full install disc. I just wiped off the HD and did a Tiger reinstall and I am going to run a repair disc.

But did what I do listed above could have caused a faulty Leopard install?

I don't know what would cause that, but I bet your new clean install will work OK.

Should I do a ful upgrade to 10.4.11, run Disk Repair and do a traditional upgrade this time?

I was also running 1 gig of ram, but just upgraded it to 2.5 gig

Nevermind....I guess this system I got was just faulty.

Really upset because I really wanted an iMac like this for years.

Thanks for the help though...

What do you mean the system is faulty? You are replacing the system. If you have a full retail install version of Leopard, pop it in and remove everything connected to the machine except KB and mouse, and reboot, holding down 'C', go to Utilities and run Repair Disk to make sure everything is hunky dory, format the drive Mac OS Extended (Journalled) and proceed with your Leopard install.

When finished connect to the net and update to OS X.5.8 using the combo updater from Apple's web site.