first update your graphic card's drivers. http://www.geforce.com/drivers
then check if it's happening in 2558. if yeah, maybe try to isolate it. download a bunch of different versions of jpcsp going down from the version you have, copy the save (ms0 folder's stuff) over to them and try the game until you find the last version that has it look right and report which version broke it.
then check if it's happening in 2558. if yeah, maybe try to isolate it. download a bunch of different versions of jpcsp going down from the version you have, copy the save (ms0 folder's stuff) over to them and try the game until you find the last version that has it look right and report which version broke it.