My apologies if this isn't the right forum. I've ripped my copy of Ys Chronicles (legit, yes) and the iso works flawlessly. I've got a bit of an OCD, so I go through and clear up space in my memory often. I heard about compressing ISOs and getting a little more space so I assumed this would be a good fix to couple with my constant 'tidying'. I followed instructions including, and this is what may have done it, 'optimizing' the file using UMDgen 4. Now the game's icon and video and music are all fine under the GAME menu of my xmb, but when I try to start the game I get a totally black screen, no splash screen or anything, and then my PSP shuts down after freezing, and I have to reboot, rerun Fast Recovery, etc. The only thing I can think of is: Perhaps because it's 2 games in one, and each one of the 2 games has 3 different BGM pools to play from, perhaps optimizing ripped something out that now causes a discrepancy. Please note that the game in ISO form plays like a champion, however compressing it "breaks" it. Thank you in advance for your help and replies.