-Connect your PSP do PC,and insert any UMD you want convert to ISO in to PSP UMD Drive.
-Press Select in PSP,change these:
USB Device to UMD Disc
UMD ISO Mode to Sony NP9660
-Now you can automaticly see UMD disc from your PSP on your PC
-Copy that file in to your's PC
-Change the name of UMD disc you copied to any of your desire
-Bring back Select Menu on PSP and change these:
USB Device to memory Stick
UMD ISO Mode to Inferno or M33 whatever custom soft you got
-Now you can copy just created ISO from PC to PSP and play without laggy UMD discs. Enjoy...
T-888