Ok the first issue is probably a problem with the new ubuntu, because I've used Amarok with my music collection on a FAT32 USB for more than a year now and I started having this problem since I installed gutsy. But now, whenever I close Amarok the drive is unmounted.  I tried configuring media devices to "do not handle" and also removing the drive from the list, but it keeps happening. (I am using gnome btw).

There is already a bug filed in launchpad>ubuntu but maybe someone here can figure out whats going on.
https://bugs.launchpad.net/ubuntu/+bug/156213

Also I have a problem with my collection browser.  When I select Group By > First Level the options are always blank, so I can't -for example- browse my collection only by year or year-album which I could do before.