Versions below 4.10.1 seem to have some stability issues in the connection with the frame and also folders inside the NAS are not visible from the Pix-Star.
Upgrading to the 4.10.1 proved to work and have those issues disappearing immediately.
How to avoid Pix-Star UPnP DLNA connection problems when using NetGear ReadyNAS 1000S – 1100 series
If you are using your Pix-Star to
stream pictures from a Netgear ReadyNAS 1000S or 1100 models be careful
to check that you run the latest software version in the ReadyNAS.