I have an 8330. I thought you could charge it with a USB Cable. When I tried it didn't show the little plug symbol on my screen and a window came up on my PC asking to insert the CD that came with my device. A friend of mine has an 8300 and he has no problem charging it from his PC.
My 9000 will not charge on one USB port at work. Try another port or a different computer. Maybe the port you tried does not provide enough power for charging.
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yep, sometimes labtops don't charge devices very well. they work with desktops however. once i tried charging my ipod on my mac with an usb and it didn't charged. then i just used my ipod power station to charge it. i really don't think charging devices with usb ports is the safest way to go. you never know when they may cause battery damage.