THIS IS ABOUT A RECENT MESSAGE ON THE BOARD :
I did have exactly the same problem and i know exactly why !!
Network Interface box outside of the house is not rain resistent, I usually put a plastic bag around to makie sure no water comes in..
Thats why when it's dry and sunny it works again..
Didn't bother to call VZ yet , but they should work on this problem (depending how old the box is )