If the animation does not appear to function as expected in Internet Explorer 6.0, review your browser's cache settings. The application was designed to work with the cache set to never (the default) or automatically check for new files. Some unexpected behavior has been observed when the cache is set otherwise.
In order to set your IE browser cache setting as prescribed, perform the following:
Select Tools > Internet Options... > General from the application menu and subsequent window tabs.
Click the Settings... button (figure 1).
Figure 1: Internet Options
Select the 'Automatically' radio button (figure 2).