[AS2] internal Preloaders don't work in Firefox browser

Has anyone had any problems with preloaders in swf (for example when loading another swf into a swf ) when viewed in the firefox browser?
test site

http://www.fourthwallcreations.co.uk.php5-8.dfw1-1.websitetestlink.com/fwcflash/

then click on one of the tabs (except Home and Community) you should get a transition animation, which in turn then leads to the loading of an external swf. When the swf is loaded the transition clears the stage and the new swf is there.

it works like a peach in Internet Explorer, but not in FireFox.

Any thoughts?
Cheers

:samus_v2: melacroso