I received some LCD displays from Satistronics today. The backlight does not appear to be working on any of them. I need to do some more investigation and I've emailed them to advise of the problem and to seek advice.
They appear to be identical to a number of display's I already had which don't have that problem (using the same dew controller and Serial LCD backpack).
I'd suggest anyone thinking of ordering them hold off until I see what their response is.
I also got some headers and pin strips from them which I use to connect the LCD, arduino and serial LCD driver to the board and they are excellent value compared to what I pay locally.
It should be a long time before I have to buy either again.