magiceye, this happened to me it's a pain, isn't it? If you know when you last successfully saved the page as you want it, try reinstating it from backup, that seemed to work for me but it does waste loads of time, especially when you've spent hours faffing to get it just right then the master template appears again!
What I also did was to literally 'save' after every change that I made. Again, time consuming but appeared to 'fix' the changes better than saving the whole page when I moved to another.
Hope this helps, if not, I am sure someone more technical than I will be along soon to shed more light!
Magiceye,
I've been having similar problems with ESW. I'm getting to the end of my tether with BT and their faceless service.
I don't understand how everytime they upload another version of ESW or add funcionality to it it seems that it has not been tested at all and it's full of bugs.
I tried previewing the site as sometime that works instead of saving it but even that won't work.
The 9-5 Monday-Friday desk is closed (As it's a Sunday) so I'm stuck (and have been since Thursday) unable to advertise a major event taking place on Monday.
BT causes more agro with their useless webhosting software and lack of support than anything else I can think of in my business life.