I don't know if it is related but I recently have a big problem : I couldn't flash my device anymore ... In fact I think my laptop's usb ports are nearly dead ! Probably because it's normally limited with 500mA and the Nokia wants more.
- when I plug my n800, the OS doesn't detect my sdcards anymore
- usb charging continues to work
- Nokia flash updater doesn't detect my device (windows & linux) while n800 seems to be in usb mode (icon on the upper right)
- my usb keys aren't detected anymore on my laptop !
- my usb mouse works fine on my laptop
- I tried with another usb cable and I've the same problems

...so pay attention if you want to charge via usb !