Hi Lewis,
From what I can tell from viewing the html code of the page (thanks for sending the link via email), it seems that the flash is not loading at all on the page. How it is designed is that the flash replaces a span placeholder, and from inspection, the span place holder is still there. From my experience this is usually from some sort of javascript error that causes the javascript that loads the flash to not execute. However, firebox's firebug doesn't report any javascript errors.
The only thing i am wondering is whether the window.onload is being called. Ahhh… I think I know what the problem might be! It could be that window.onload is called again after my javascript code, and thus overwriting the onload function. Now, I don't have any proof that this is exactly what is happening, but it is the only logical conclusion.
I got an idea that I want you to try. I was just about to close my computer and go to bed, but try this out for me and let me know if it works.
Go to the plg_easyflashuploader.php file and replace line 161 (or comment it out by putting '//' before it) with this:
This should work perfectly. It uses mootools' window.addEvent instead of window.onload.
Please let me know if it works out.