I have a Samsung Smart TV UE40D7000 and my router is a Netgear VMDG280. The TV is connected to the router by WiFi. Signal strength should be good as the router is near the TV and my laptop, ipods and android phone all work in the garden which is beyond the TV and through the wall.
The TV works OK on the internet for iPlayer but every so often it loses the connection and reports no WiFi. This can only be fixed by switching off both the TV and the router and turning them back on again. It sometimes doesn't happen for a few days, then it happens three or four times on the same day.
No other devices attached to the router by WiFi are affected and continue to work when the TV is reporting no WiFi.
I think this can't just be an issue with the TV because rebooting the TV but not the router doesn't fix it. I have to reboot them both.
Similar experience - new router and SH to modem mode finally seem to have fixed issues with the connection to my Samsung - the TV wants dual band ideally and the SH is not true dual band, it can only support one band at a time - if your on 2.4GHz its very congested, 5GHz signal will be weaker. Gneral performance from the SH is poor even after tweaking the settings - I think the DHCP side of the wireless is a bit flakey and just upsets the TV to the point that the connection fails.
The Superhub is not the best router available - particularly the wireless connections, and my TV connection got worse going from R35 to R36 firmware, frustration with the poor SH wireless finally drove me to purchase a quality dual band router. I'm not sure they will ever fix it with firmware patches although attempt 37 is supposed to be on the way! Some good deals on homeplugs about at the moment (less than £50), might be a painless fix.