Praise where it's due
I checked the Forums to see if anyone else had reported it, nope, so I opened a Support Ticket via my Linode Control Panel thing.
Within 4 minutes of submitting the ticket I had a human reply requesting some more information (that I should have supplied from the start, my bad) and within 4 minutes of giving them all the information they required I had another message saying the problem had been fixed !
Compare that with my old ISP who would just say "can you E-mail the problem details and we'll look into it".. then I'd wait a few hours.. then either I'd have to chase the problem up again, or it would magically work again without any notification from my ISP (presumably they fixed it).
OK, so some may say things should never go wrong.. but that's too idealistic; even with the best will in the world, stuff just goes wrong now and then. It's how it's dealt with that's important, and I've got nothing but praise for Linode.