Yoshihiro & Team Wab have been busy and released a new piece of software that fools your PSP into thinking its been flashed to v1.51, 1.52 or v2.0 for games that do a check.
This software is for v1.00 and v1.50 PSP Owners, heres some from the nfo:
Yoshihiro and WAB are proud to bring you ÛÛ
²Û The First Firmware Trickz for Gamez that need Firmware 1.52 Û²
²Û to run on your PSP and Cant Run UPDATER 1.52 or 2.0 ²±
²Û The System think it's a PSP v1.52 ,v1.0 ,v2.0 ±°
²Û even if its a v1.5 or 1.0 .
Note - I myself havent tried it as i dont own any games requring the firmware update.