Can’t save

I am trying to update my web site. something is stopping me from saving my work – on almost any page.
I have cleared the cache on the site, as well as clearing both the cache and cookies on my browser [Firefox]. I have deactivated all plugins that are not proven in the past to work without problems.
I do not know where to look for this problem. Any thoughts???

The page I need help with: [log in to see the link]