Preloader Intermittent Problem

I’m having some intermittent problems with the loading of my flash-based website ([COLOR=#990000][/COLOR]) and I can’t see anything wrong with the code. Basically, on occasion, the preloader won’t start and the loader page (index.swf) doesn’t clear when the Red_Herring_CG_Site.swf loads leaving the logo and preloader superimposed on top the site. Refreshing the page gets rid of them, but doesn’t really solve the problem.

This only seems to happen with IE7. It works fine with Firefox.

As I’ve said, I’ve double-checked the code (it was actually taken from a book by David Morris specifically on how to create a flash-based website) and it’s not a consistent fault, which is very frustrating! I don’t expect you to check the code, but if you have any views on what might be causing this it would be very big help.