I've had a try sync-ing with Karmic 64-bit and my N900, using the same technique for previous Nokias like my N95. This means grabbing the SyncML Server channel on Bluetooth, then using multisync. It always hangs on the Bluetooth connect. I tried logging but the OSYNC_TRACE produces huge volumes of data which doesn't mean much to me :-(

I have got WinXP running in VirtualBox with Nokia PC Suite - and that reads the contacts off the N900. Pretty much all that is needed to make this happen is to add the N900 as a USB device in VirtualBox.

I've copied my /home folder off the N900 and will pull that copy to pieces later to see what is going on with the file system. I like to know where things get stored :-)