file sizes

[mechhybrid]

Hi I have recently just purchased a no solder for my version 4 ps2, I have burned a few backups and they have worked fine. There are about 20 though that just won't boot. I am using Swap Magic, I tried GameShark v2 , but still could not boot the discs I was wanting to, and I was wondering if it was the file sizes?

The largest backup I made (using Verbatim CD-R) was roughly around 737mb, and it worked fine, now i can't burn and run backups that are over 760mb, could this be the mod chip? And yes I know how to burn correctly, I have read all the FAQs and tutorials, I know how. Any suggestions would be great.