[jbrew]

For me NAS media playback (with FTV) works better/faster with NFS mount compared to SMB. I had no issues on ATV2 with NFS but with FTV that did not work. Read worked after I added 'insecure' to export file in NAS. Write for Thumbnails did not work even after adding anonuid to NAS exports till I saw Diegomejia's post - http://forum.xbmc.org/showthread.php?tid...pid1690670 , and it worked after a update (I did not do reinstall).
Here is a recap of what I did to make NFS (for linux based NAS) work for FTV. I believe these changes on NFS mount is Android related and not specific to FTV.
In this example - 192.168.1.101 is the ip address of FTV and 192.168.1.102 is the NAS.

In advancedsettings.xml for Thumbnail cache (write to NAS) add this in substitute.

<to>nfs://192.168.1.102/mnt/path_write/FTV/userdata_spmc/Thumbnails/</to>

If you have multiple xbmc installation in FTV, use different folders for Thumbnails in those xmls.
Note I tried with userid and password here in path initially. That works in ATV2 (without insecure in NAS exports file) but does not work in FTV. To circumvent I had to update my exports file in NAS and add anonuid/anongid.

sources.xml remained same as what I had in ATV2. As mentioned above it worked after adding insecure in NAS exports file.

nfs://192.168.1.102/mnt/path_read

Assuming you have a linux based NAS with a directory where you have provided read access and another directory with write access.
Edit your exports file (/ffp/etc/exports) with any available editor (vi).
By default on my NAS I had this on exports file.

/mnt/path_write 192.168.1.0/24(rw,no_root_squash)
/mnt/path_read 192.168.1.0/24(rw,no_root_squash)

I changed exports file to

/mnt/path_write 192.118.1.101(rw,all_squash,insecure,anonuid=501,anongid=502)
/mnt/path_read 192.118.1.101(ro,all_squash,insecure,anonuid=501,anongid=502)

For starters, you can get anonuid and anongid (group id) by using command like this in NAS command line (use telnet to get into NAS if you have access) and it will vary depending on your NAS set up.

cat /etc/passwd

Reboot NAS to get the exports in effect. Clear cache, clear data in FTV for XBMC, and then use -r option in desktop to update xbmc installation for NFS write to work in FTV XBMC.