Reading problem

[OURKID]

Here's one for u all.
I was attempting to back-up my World Championship Rugby game and as i have done many times in the past , put the original in the dvd/rom and using Record Max now 4.5 imaged the disc and burned it with my lite-on dvd/rw but when i tried tp play it in my ps2 it did not recognize the disc.
So after much mumbling i discovered that when i checked the size of the global image in the disc explorer and the one seen when using the dvd/rom was smaller than if i used the dvd/rw.
Now i know what you think so i changed the dvd/rom for a new one but the results were the same.
For your info the dvd/rom is running as slave on my primary ide cable with the h/d and the dvd/rw is running as master on secondary ide.
I have a 1.4ghz athalon with 256ddr memory and a 60gig h/d running xp-pro
I have used the dvd/rw to do both processes and got a good back-up so no problem there...but a little annoyed that i may have wasted money on a dvd/rom i don't need.
Wondered if any of you peeps could shed any light on the subject???
Cheers in advance.