kieran, its a wire that links your computer to your ps2 (usb to usb), u can then move file of you memory card that u dont use but dont want to deleat on to your computer, or download files to put on tot he memory card, like a pes 3 options file, if u want more info look at the stick thread.
scully, i know it sound silly but blow the connecters some time dust get in them. other then that i dont know, unless u reinstall the x-port program