Please go to your local GameStop, buy a $50 ps2 with hard drive, install your game onto it. Run updates. Wait 10hrs. Log on, and use this system as a testing system. When you finish your update bundle for the ps2's, please, please, please, run it on this system first. Make sure it works, and most importantly, make sure it fits in the 10gig partition that is set aside for FFXI. Don't change any default parameters, use this ps2 to see how some people still play your game and know the limitations of the system that you married yourself to 10yrs ago.
It sucks that this machine will be the brick around your ankles that keeps you from updating this game to something better, but that's the situation you are stuck in, and unless you are willing to pull the plug on the PS2, you MUST take it into account EVERY time you do an update.
Btw, thanks for all the awesome updates the past 9months, aside from being too much for the PS2 to handle, you're doing a hell of a job. Add <petmpp> and let my npc's be affected by sambas, level to 75 and last longer than 30 mobs and I'll be happy.