its not the problem with memory stick. i had many experiences. problem is the camdriver. i used good speed drivers and slowly drivers. i found a simple reason. they progmammed them in different ways. but i don't know how to programme them. when you open the camdriver.dat with wordpad, you can see 2 different programming patterns. i tried to edit some iso data. but it doesn't work. does anybody knows how to programme of edit a camdriver? wish you all the best...!!!