I tested yesterday coonecting the N900 as an usb storage device to my notebook running Karmic, and I'm sure there is something weird in the usb implementation.

At first try two N900 icons appear (there's no sd card in my N900). Sometimes, I cannot even browse any of the icons. Other times, one or the other of the two icons change their image to a "sheet of paper" becoming totally irresponsive and cannot even be opened in Nautilus.

Sometimes I have to unplug and replug in order to get one of the icons (the one with DCIM, Mac OS, ...). I was going crazy looking for MyDocs directory until a I learnt by reading this thread about the hidden directories.

With my N800 it works flawlessly.

Has someone reported a bug?