To force refresh:
On Windows, use one of the following:
Hold the Ctrl key and press the F5 key.
Hold the ? Shift key and press the F5 key.
Hold the ? Shift key and click the Reload button on the navigation toolbar.
Hold the Ctrl key and click the Reload button on the navigation toolbar.
On Mac:
In Camino and Firefox, press Shift-Command-R (or hold Shift and click the Reload button). In Safari, hold the Option key and press the Reload button in the toolbar.