To remove those dead drive icons I just edited /etc/fstab and appended "x-gvfs-hide" to the mount options of those partititions like this:
UUID=ea5ad8...de2 /media/sda1 ext4 noatime,errors=remount-ro,noauto,x-gvfs-hide 0 0 Immediately the icons disappear , even without reboot. So, it's just ea configuration error which reports partititions marked "nouser" as removable. Whether it is xfdesktop4 or even a bug in gvfs I don't know.