1. Yes OPL (official- & beta-version) and PS2ESDL in it's newest test-version, both suport loading ISOs up to 4GB from a FAT32-formatted USB-Storage-Device.
Originally Posted by aejae
2. ISOs must be renamed correctly. Look at the OPL-Tutorials, which are linked on top of every page here.
3. You can re-create the ul.cfg with USB-Utilv2 (it has a recovery-function which even works, when no ul.cfg-file is present at all).
PS2 V7/DMS3 V2 (FW:2.4b7); Seagate Baracuda 200GB
PS2 V7/CC1.0 (FW:34 hacked v2 BM:2.1.6); Maxtor DiamondMAX9 PLUS 160GB
PS2 SCPH-30004R; NoMod+NoLaser
3xSony MC 8MB
MAX/Datel 16MB with Boot-CD
Custom FMCB 1.8b+ Beta-Build, my AIO 0.5, Sony&xRhino-Linux