I've pretty much done all it instructs; latest HX edit, installed the latest driver etc. It's at step 2 #3 that HX Edit keeps saying 'connection interrupted' and that's where we stop.
Tantalizingly close, but no cigar.
I bought a new usb cable today, tried both USB ports on the MacBook etc. The guy at the music store today thought there might have been a version of HX Edit a few releases back that have some components in it I don't have.....or something.
It may be time to try to contact Line 6 and get a service ticket, or just effing call them.
update: I just did a service ticket with Line 6. We'll see what we'll see I guess.
Thanks again!