I took my USB stick back to Curry's and they seemed very surprised that it wasn't working and gave me a new one plus £2.99 back on my card as the new one was cheaper. I'd have rather had my money back as I am worried the same thing will happen again.
I do have a portable hard drive that works with the TV but it's annoying as it keeps making a strange noise every now and then so if I want to keep using that it means I'll have to keep unplugging it every night as the TV is in the bedroom. I also prefer the fact that the USB stick is invisible once it's plugged into the side of the TV.
This time I have kept the receipt and if it goes wrong again I will see if I can just buy something else for the same value rather than keep going through endless USB sticks
Lyn