Quoted from Steve44:
I don't know if it was the checking of the MD5 that has scared it into making it work but I promise I have done
nothing different to what I have been doing countless times for the last 5 days!
Thanks again to Eric, Jherre6, sataneatscheese, LouMatt, metallik, MuttweFudder, pinballinreno, Calfdemon,
dnapac and Coyohtay for your help, time and trouble!
(I did have the full file name, I was just shortening it to show the end was correct)
YAY! It just needed to know that you were getting serious...
Inconsistencies like this are generally a loose connection or flaky cable.