Ok, to completely rule out the page caching, can you reactivate it temporarily, flush the page cache and then deactivate it? After you do that, can you also make sure the rules the caching plugin are removed from the .htaccess file? Often times I’ve found the caching plugins do not remove those rules so the .htaccess will still point to cached pages and since the plugin isn’t active, the cached pages are not refreshed as they should be, so you end up severing the old cached version of the page. You can verify that your serving a fresh page by making any small type change to the page and then update it, log out and make sure the change you made is reflected in the page.
If after doing this, it still doesn’t work, I’m going to need a temp admin account so I can take a closer look.