Wow . . . I was just about to post about having the sg3 hooked up to the pc. About a month ago, My phone would not communicate with my pc. Never tried it on my laptop as a means to diagnose whether it was the phone or the pc causing the issue. What I eventually did was remove the battery, sd Card & sim card, & rebooted (the phone) & all was good after that.
Well, 2 hours ago, I rebooted my pc, & suddenly, I lost my sound device, windows explorer crashed to the point where I couldn`t open control panel, & the start button was non-functional (windows xp sp3). After 3 reboots, still no dice. Then, it dawned on me that all these pc reboots happened with the phone hooked up to the pc via the usb cable. I disonnected, re-booted the pc & . . . how bout it . . . PERFECT !!
Wow.
Moral of the story . . . (at least for me) Do not re-boot your pc with an active connection to your galaxy SG3 . . .