Basically you need to buy a switch - ideally a netgear one. You need to connect everything via the switch, so:-
Thomson Router connects into switch
Tv connects to swtich
Readynas Duo connects to switch
I have the same router as you - its crap!! lol - still once you invest in a cheap switch then your tv will show the readynas 100% of the time (I ended up getting a 1 gig switch)
Also if you have an android device then this too will now see the readynas - so you can stream your music, photos, vids as well.
This is the one I am using http://www.pcworld.co.uk/gbuk/netgear-g ... 7-pdt.html
look around - i think i paid £20 for this and £35 for the 8 port
(well I've now got 2 of these plus the 8 port one)
Works REALLY WELL!!
Wirelessly - Until I got the switch between the nas and the network - my wireless devices (tablet/phones) could sometimes see the nas. It seems that prior to getting the switch in place, in order to see the readynas you had to a laptop or pc switched on - on the network - weird. Now though I can simply have the router, switch and nas on, then whatever i switch on tv (now wired), phone, tablet - they all pick them up (2 readynas now) 100% of the time.