1546 Preloading of SWF/JS problem

I've been having some pre-loading issues with my swf content. The preloader within the swf calls an external 'swf' and '.as' file to show an animation referring to the number of bytes loaded within a swf file, and when all the data is cached it then plays the flash file. When this is displayed on the first ([login to view URL]) page it works fine. However, we have a javascript function which loads a new html page and a new swf page on clicking a button (which can be either within the swf file or on the html page itself). When this happens, the new swf file does not seem to load correctly, but instead shows the background colour of the swf (presumably until the swf has loaded fully) and then plays the preloader together with the main content all in one go. As a result, we are therefore left viewing a blue box (the background of the swf file) for a long time until the swf plays (and then we get to see both the preloader and content). We have tested our swfs thoroughly and know it is something to do with the javascript function. We're thinking that the 'change_page' function within the html page, is causing the swf to load as one large object fully before it being visible, rather than allowing then first couple of frames to be loaded (i..e the preloader). So, we either need a fix for this, which may be a modification of the change page function or it may be something we can do in flash to stop it happening...