if you are using Internet Explorer:
make sure the Status Bar at the foot of the screen in on (if not, right click in the Menu Bar or Command bar area at the top, and click it. There will be a Privacy Report icon showing the cookie status of that page. If it looks like a red circle with a diagonal red line, some cookies are being blocked. Left-click on this icon and select "show all websites"
DIYnot.com should show "accepted"
if not, right-click on it and select "always accept cookies from this site"
It is OK to "always reject" advertising tracking cookies.
Maybe you have an internet security package that has set your Privacy Settings to high safety.