Using a different computer's (same model, though) installation disc?

Ok, here's the deal. I just bought a 2.4 15'' MacBook Pro Unibody. I tried to wipe the drive and do a clean install from the system software installation disc that came with the computer. Three tries, failed each time. "Faulty disc" is what it said.

Well, I had to get a project done, so I borrowed same system software installation disc from a friend who bought the exact same computer on the same day. The disc worked fine! Leopard up and runnin'!

But I still called Apple to get a replacement disc. They said they did not recommend using another computer's disc to install. Well I'm thinking "dude, it's the same exact computer! So it must be the same disc?"

Anyone have experience with this? Should I wipe and reinstall AGAIN (NOOO!) after I get my disc. After a few days, it's been working just fine as is.

Thanks so much!

 

What about taking the hard drive from a 15 inch unibody MacBook Pro (Leopard installed using the installation discs from a 15inch model) and putting it in a 13 inch unibody MacBook? Will it jack it up? Both computers have the same specs, the only diff between slightly better graphics cards in the 15 inch, right? I'm trying to do a hard drive swap and hoping there won't be a problem. Thanks!