I have just discovered the strangest thing.

if I exit the folder, then re-open the bat file, it runs, but still validation errors / low hash rate.

But if I exit the command prompt, then try to re-open, it doesn't work. But if I leave the folder again, then open it, the command prompt works again. I've never seen anything like this and it only happens with the latest version.

K7x32 does not validate
Y7x32 does not validate
Lowcaser versions don't either.

GTX670 SLI. But with 12-18, it validates @ 570KH/s. This one shows around 697KH/s, but every other one fails to validate, so there's little point.