I have just checked with the hosting provider and they confirm that there is no server side caching system. Until now I have been using WP Super Cache which was working fine for logged in users.
Thanks for that, something strange happening with Super Cache. I had cleared it a few times but it seems that there were still some expired pages causing a problem. Not sure!
Anyway, thanks for your time!
This reply was modified 7 years, 2 months ago by confusedneedhelp.