So your dumps are burned and not retail discs?

Actually I own those games, but I tried this one on a friend's chipped PS2. I'm just wondering why didn't worked the burned game and what are that "extra" weight on one image.

16-18x is really much, i would not choose it, burn it 1-2x it is much enough

Mainly "load errors", I mean, sometimes it stopped in the first loading screen and didn't finish the loading; other times, the game was a little bit late but it loaded just fine and I could play it, but that time I only played some minutes because when a video sequence arised, it just frozen and I had to reset the console.

After many tries, it were always the same errors, so I decided to verify my disc against other images from the same game, so I downloaded all the images I found (from different uploaders of course); I had downloaded a total of 5 images and all have the same hashes and size, so I think my disc isn't failed because it haves the same size and hashes that all the other images I downloaded but it refuses to work at my PS2 console, so the only I can think is that I burned at a very high speed (16-18 x, high quality media), no more, no less .

But, here begin my real question

I downloaded another image and here are the strange fact:

It haves the very same content but it weights a little bit more and haves different hashes that all the others images I downloaded.

How could this be possible?

I compared their raw, hexadecimal content with HxD, and effectively it told me:

Thanks in advance.

P.D. The game link is: http://redump.org/disc/8121/