system crash with limewire basic

i have normal limewire installed on mac os9.2, and everytime in a download, or when a download reaches 99% ,the programm shuts down, and the whole system breaks down
when i am downloading, suddenly after several minutes,
limewire shuts down and the whole system breaks down,
i use a apple powerbook with mac os 9.2,
and the mouse cursor breaks too, and you just see a pack of pixels,
when you try to shut down the program by forcing it, the system is already crashed, and you have to restart, can you tell my why ???