The earliest PS2 console models (SCPH-10000-SCPH-39004) have a hardware bug that causes some games to either not boot at all, or crash while in-game after boot, when burned to an 80 minute/700MB CD-R. This happens with mod-chips and soft-mods on these models of the PS2. On PS1 consoles, the same PS2-problematic 80 minute/700MB CD-R has no issue (besides slower seeking in comparison to lower capacity 71 minute/74 minute discs). The only way previously known to work around this PS2 hardware bug was to instead burn an affected game to either a 74 minute/650MB or a 71 minute/620MB CD-R.
Tonyhax International as of v1.5.4 now has a software-based fix to ensures 80 minute CD-Rs boot correctly. This fix is only applicable while Tonyhax International is reading the 80 minute CD-R. It can’t do anything after the game starts, since the game takes over control of how it reads the disc (which can potentially invoke the same issue). Still, the software-based fix gets a lot of games working just fine that have this problem. If your game is still being problematic, patch the disc image with my psx80mp and burn a new CD-R to fix this issue for good.