This is mainly for sharing my experience.Suggestions are of course welcome.
It is quite annoying that when I power off (5 second on remote) my wd TV live and after some time I switch it on, it does not connect to WiFi. As WiFi router I have a DLINK DIR-845L.
It appears something related to DHCP (i.e. if I use a wrong password I have a immediate message of wrong passwd, otherwise I have to wait till a message saying check password).
At the router side I could not find any trace in log file of WD TV live DHCP request.
It is enough to disable and enable radio to have evrything working.
I cannot locate the problem without checking what there is on air. I would think to some problem with the router, but it is perfect on all my devices!
How I have solved:
I have enabled on the DIR-845L the WiFiguest zone (I.e. two SSID are broadcast on the same beacon). I cannot tell it always works, but it is very rare it does work.
PS: Remeber that guest zone does not allow access to other WiFi devices, so you have to set in WD the not guest zone SSID as default, or releselect