It is typical - the fish never play when you need them to be on form! As you know I won't get in a boat or any such device as I enjoy fishing from the bank, and making tea, however on many occasions the boat is actually used to fish close in on the shore that the wind is blowing onto. In effect the boat lets you fish the biggest bit of wave on the loch where it breaks onto shore, weed beds, or skerries. Also it is possible that you identified the problem yourself when you said the flies were all around your car - with little wind like that perhaps the fish were sitting relatively close in where the wind was blowing flies off the bank? With so little wind they might not have been too far out.
I did think that, it was just odd that I then caught straight away from the shore. The water was crystal clear and surprisingly shallow. I'll have em next time! Cheers G