I've just heard that Doocot was closed on Thursday "due to unforeseen circumstances" although the Lighthouse was still open. I've been trying to phone to find out if it was a temporary closure or permanent, but Doocot's number is just ringing out and the Lighthouse's number has been disconnected!
In a rush to find a new venue, I'm going to recommend Esquires, a better than average chain coffee house which is right beside Central station, so easy to find. Details as follows and note the "Click here for a map" link.
http://www.esquirescoffee.co.uk/public/stores/26Unfortunately I have no idea on the sort of food they provide in store as I've only sampled what they provided to a National Autistic Society training course I was on a few weeks ago.
If anyone else has a better suggestion, bearing in mind the need for some people to have just a coffee rather than a meal, please make it quickly!