wierd problem

[cool_dude_2000]

well i have never played ps1 backups on a ps2 console. my ps2 is modded but i don't know which chip, mainly because people in our country don't know much and i also don't know . anyway, when the first time i played a ps1 backup on my ps2 console(by turning on the main power and and pressing and holding the standby button until the eject button turns blue... procedure) and then i play the game and every thing goes on normal except that after playing a ps1 game and i turn the console off from the main power switch and then i play a ps2 game, at the opening screen one of the transparent cubes had turned into white colour!!!. and this happens each time i play a ps2 game and now i have 3 of them(which means i played a ps1 game on my ps2 console 3 times)

does anyone know why this happened?
Also is there a way to fix this and how to fix it?

any sort of ideas or help are greatly apprecaited

thanks in advance