Your computer's usb hub could damage micro-usb port of N9.Send it to the Nokia Care , they'll replace with a new micro-usb port.Then try to use another usb hub , this happened me 3 times

ofcourse you can bypass not found error by cold flashing the firmware, but for most people nokia care is easiest solution.

The key issue is that it no longers appears to be charging. Plug in the standard wall charger and the device wakes to show the Nokia logo but also shows the USB connection logo rather than the charging logo.

If it was out of warrantee i would crack it open and replace the battery with a charged one and confirm this one way or another.

As it is I am awaiting a return call from Nokia as to what action they are taking. They could not answer immediately as they needed to speak to a specialist team. That could be good news or bad!

Well after 6 days it is back, repaired and working well.

I have a back up but one thing I truly love about the N9 is that after 10 mins of setting up accounts all my data and contacts are back. Just folder set up and screen org to sort.

I have been using my N900 in the interim and realise just how much better for me the N9 is, especially the screen vibrancy.

The repair note just said software update.