backups problem
 

I have a v4 ps2 modded with a neo2.5 dvd key. There are two different modes that u can boot cd-r backups with. If i boot a game with method 1 the game works flawlessly and the lens doesnt make clickin sounds. But if i boot a game using method 2 the game loads and everything but the lens makes loud clicking sounds. I dont think its the media because the games boot flawlessly in method one with no skipping. Also not all of my backups boot in method one, so some i have to boot using method two and i get the loud clicking sounds. Does anyone know what the problem is?