Thanks Dave (slidey)
This issue has now been taken out of my hands. I drove to work on Tuesday and whilst on the motorway a humming noise developed and got louder and louder even though no braking had taken place, Fortunately I was very close to my exit. The brake had seized on again and was smoking heavily. I waited 10 mins and it freed off again completely so I drove to work and got it into a local garage. Diagnosis was knackered calliper, also discs and pads which I needed anyway.
I've not done enough mileage yet to know if it is completely fixed but so far so good, there is a slight dragging when coming to a rolling stop but I'm unsure if this more than what is considered normal.
Either way its now the garages responsibility which gives me some relief.
BTW I asked a mechanic in my local Mazda dealership what they use to lubricate the guide pins and the response was "copper slip". I had read somewhere else about rubber grease but none of my local motor factors stocked it or knew of it, my next stop was probably going to be Ann Summers
Hopefully my issue is resolved and if not I hope this post will provide a good reference for anyone with a similar issue in the future.