In reply to Paul Atkinson:
I'd agree it's airport dependent - put mine in my bag, flying with EJ from Manchester, didn't mention it at check-in - happy days. flown twice from Leeds with it, both times lengthy teeth sucking from check-in and security, allowed through eventually - neither had ever seen one before (these were both last year) and were amazed when I showed her the IATA rules (which I have attached to the cylinder). On all occasions I'd called the airline beforehand (and have an email from Easyjet that I have printed out).
No worries at either Geneva or Innsbruck coming home.
Of the low cost airlines I've called FlyBE were bloody clueless - Indian call centre by the sound of it, and involved lots of messing about at 10p per minute (and this was this year).