WordPress issues

I’m trying to edit a site with wordpress (site was originally designed with it) and there are 2 pages that when I click on the pages list then Edit for the page(s) in question, the editor shows content that is several years old.

In the editor I can change the title of the page and it will display correctly on the preview and published pages but I cannot change any of the page content.

If I click the Preview link it shows the page as it is currently.

Edit page: (this is the content that is several years old – I can make any changes here and it does not affect the preview or published page). I can however, change the page title and the changes take place in the preview and published page.

Preview page: (current content)

I have tried several other pages on the site and any changes that are made there are reflected in the editor and on the published site. Are there some strange "locks" or something on the two pages in question that I don’t know about?

edit: I should add that I know *just* enough about this stuff to be dangerous so please speak clearly and slowly.

Does it matter whether you edit in visual or text?