Several things to do to get the mount to work properly with the current Midori image....
First fix the mtab file.....
ln -s /proc/mounts /tmp/config/etc/mtab
freeze the config
create a mountpoint in the /tmp directory structure somewhere
use your mount command to mount the share...you don't need the workgroup option usually.
before you freeze you need to unmount the share....freeze sometimes will try to encapsulate
it also depending on where you create it.