Website problem

For years I have had a tab open in Chrome and/or IE with no problems. Yet a few days ago I was unable to open UK Dragonflies using either browser; and strangely I cannot open it on my iPhone using safari, either on wifi in my house OR 3G outside? Can anyone help please?

It opens for me in the latest release of Chrome stable. It may be your cookies are causing it. How often do you clean your browser history/cookies/temp files? Maybe try clearing data from the browser(s)?