OS X Server 10.4.8 + NFS Userhomes problem

Hi all. First time poster - long time lurker. I've also posted something similar over @ macfixit - just to widen the chances of getting a useful solution to this headache. I've got a complex little problem concerning NFS Userhome's. The backstory to this, is that I have the requirement to make NFS Userhomes work. Why? I'm building a large Sun Microsystems SAM-QFS SAN environment. As some of you are probably aware, AFP frontend exports/services don't magically exist in the Sun environment, let alone under SAM-QFS control! ;). Essentially, we need to pop OS X network userhomes on BIG SAM-QFS controlled NFS exports because, for the purposes of enterprise redundancy, control and resilence, I cannot rely on XSAN/XServe RAID based solutions. It's far too big, far too mission critical, unfortunately - added to this that I require true HSM (hence, SAM-QFS is ideal). The scenario/little test environment in my lab: 1. Server - Mac OS X 10.4.8 and 10.5 [192.168.0.11], running OpenDirectory services, AFP, NFS, FTP for user authentication etc on x86 MacBook Pro 2. Server - Solaris 10 x86-64 [192.168.0.10]. Again, not running on a Sun box yet - just a tidy virtual machine for the time being. From this server, I have a large NFS export sent out, targetting a specific address on the network [192.168.0.11, which is the OS X Server], using the root=@192.168.0.11 and root_no_squash options (this prevents locking and permissions issues, sharing the imported NFS mount in WGM, under OS X). 3. Client. An Intel MacBook 13" [192.168.0.12] that has been bound using "Directory access" tool to the OS X server. It detected the Directory node and locked directory access to it instantly. No probs there. So, we know the components of the environment now. The NFS export from the Solaris server is imported into the OS X 10.4.8/5 server using the little option WGA gives you, to automount. If I run a df -h from the command line, it shows up as a correctly automountable volume under /private/var .....blah blah. So, with this in mind, I clicked "share this item" in the sharing section of WGA. I then selected the ability to allow it's use for UserHomes and ticked "create mount record" etc etc. I selected Export via NFS and specified a client (being 192.168.0.12). Next, I created a userhome for a new user (lets call him test_nfs_guy) and selected this NFS reshare (as it goes "through" AFP, so it seems!) and sure enough, if I look in my /export/OSX_Userhomes on the Solaris boxen, there is a new home-dir created, with the appropriate skeleton structure all in place (Documents, libraries, music, public), all the normal directories one expects to find in a home-dir. It's communicating fine with the NFS export/import, or so it seems. So, time to try and log a client in. So - lets log test_nfs_guy in on the 192.168.0.12 MacBook 13". It pretty much instantly authenticates with the OD - and allows the login process begin. Crunch crunch crunch. Then something less than happy happens -_-. The message "home folder for user test_nfs_guy is not located in the usual place or has..." comes up on login. So, we are logged in just fine - but the home-directory has not mapped???! The odd part? If I go-->connect to server then pop in 192.168.0.11 [the OS X server] AFP will connect me and authenticate me to the "home directory" which is living on 192.168.0.10 perfectly fine! I can see it. I can write to it, I can read from it - yet I can't have it mount as a UserHome on login of a WGA controlled user! Very, VERY frustrating. What am I doing wrong guys? Thanks. Any help would be most appreciated. Cheers. z.