I have an issue where my screen/page seems to be caching, so I can't view existing products...

If I clear the Cache in Cache Management it works perectly until I create or edit a product and also if I use CMD + R to refresh (on a mac) or Ctrl + F5 to force refresh (on a windows PC) it works after a few attempts (sometimes 3 sometimes 10).
Not sure whats causing it, any ideas of where to look would be really helpful
Thanks