Station graphs, Firefox and IE

HI, on my PC I have Firefox as my default browser, I had noticed that on my website the station graphs were not updating everyday, when I looked today,(9 April) the latest graph was for 3rd April. Just to see how things looked on IE I used that to go to the same page and there the graphs were for a date in march, oh and while typing this I checked on my phone using Chrome and the graphs are up to date. I am assuming this must be a cache problem maybe?

Yes it could be the browser cache - if you press Ctrl + F5 it should force the browser to reload the page and show up-to-date graphs. If it does then it was the cache showing old images.