Bizarre cache issue

How do I force the browser to always refresh parts or all of the content?

I have a bizzare issue where the browser is caching parts of the site. For example I have a 'History' for a model row in the DB. I add a comment, update etc. If I visit the History page then navigate to another action that adds a history then return to the history page it is the old version. If I refresh I get the new content. I am now finding these issues everywhere in my site.

I can confirm that there are no hits to the server so it's not a Rails caching issue - seems to be browser based.

Any ideas?