Readynas Duo is visible but not accessible

[remoh1]

I have just had some structured cabling installed and now have the following set up

all wall ports are connected to a 16/24 Way Gigabit network Switch
A netgear D6300 wireless router with a cable connection to the network switch
A wireless repeater to boost the wireless at the far end of the building

If I plug the readynas duo into the netgear 6300 I can see the device on the network and access it on the wireless network from my mac opening and saving files with now issues

if I move to an area of the bungalow that is covered by the repeater I can see the readynas but cannot access it.

if I plug the readynas into the network switch then again I can see it from anywhere but cannot access it

I'm assuming its a config thing but what? any help gratefully received

[mdgm-ntgr]

Does the I.P. of the NAS change depending on where you plug it in?

Which device gives out I.P. addresses on your network?

[remoh1]

ip address remains the same and the netgear d6300 is handing out ip's

[StephenB]

Can you ping the NAS by its IP address?

What failure message do you get when you try to access it?