Thanks for your reply.
My ISP also supports IPv6 and has done so for the last few years (sounds like they were one of the first) and my modem has been enabled for it. Because of this, using Hideaway is a bit pointless for websites that also make use of IPv6 if one wants to be completely anonymous, like Facebook for example. I see Facebook can still see my location, albeit it two different ones, as every website that makes use of IPv6 could also, though admittedly there may not be many if ISP's don't support it.
For the time being, certainly until the next Hideaway that supports IPv6, I have since gone through the settings on my modem and disabled support for IPv6. Now I see for Facebook that my location is unknown.
