Help Lock/Unlock Sounds Zio

[oplayboy007]

I just bought and rooted a sanyo zio that runs android 2.2. but i cant find a way to change the lock unlock sounds. I have the files in ogg format, i put them in the ui folder, named them lock and unlock but the sound remains the same regardless. when turning on the option to play the lock unlock sounds theres an alert sound that goes off automatically but its not the one i attempted to set. is there something im missing or doing wrong here?