The forecast images are not updating?
In most cases, this is most likely something on your computer. You can imagine how full our inbox would be if the forecasts were offline!
Why is it happening - usually to do with "cached" images - your browser tries it's best to save images so they are re-downloaded over and over, and it sounds like this might be what is happening to you. We have special "cache-busting" techniques to get around this feature which works 99.9% of the time.
To fix the problem, try a "forced" refresh: If using Microsoft IE, or Firefox, hold down the Control key whilst clicking the refresh icon/menu option. If you're using a different browser, have a hunt around the menus and options pages for features related to "Clear Cache"