http://community.spiceworks.com/topic/439085-smb-share-slow-to-load-in-finder-on-macs?page=4

There seems to be a solution that involves Samba and vfs_fruit.  Its all way over my head to be honest but it does appear like this chap has a solution although it seems a complex one.  As you can see they have suggested me talking to Netgear about implementing it so it would be useful to hear the experts views.