Not sure if this is a similar problem, but with my Gigabit G4 (dual 500 mhz, HK Soundsticks), I have recently been unable to wake from sleep properly. When my Mac attempts to wake, the screen is frozen and there is a strange clicking sound coming from my soundsticks. Last night I went into sleep mode with the soundsticks unplugged, and it woke from sleep fine. . . .crazy USB speaker interface. . .