Help Wi-Fi Signal/Streaming Problems

I'm getting N7 wireless connection via a Virgin Media Netgear VMGD280 router

Connection says signal strength Excellent.

2 probs:

1 - When streaming video the stream locks up after a few of minutes use and the circular progress symbol rotates. Sometimes message 'internet connection lost - retry ?' comes up repeatedly . I've changed the DNS number to the 8.8.8 one recommended in another thread, but still clunky.

2 - when I switch out of standby via the security pattern the wi-fi signal indicator bars are greyed - it still says signal strength excellent but I need to switch wi-fi off and on again to get the blue bars and working signal.

Any suggestions to improve above much appreciated, thanks