Despite all effort, Preloader still not displaying first

[]I don’t export a single thing to the first frame.
]I removed all references to absolutely everything (except my preloader - which is about 10kb) from my document class.
[*]The only reference to my main class is a MovieClip which links to it placed on Frame 3 (Frame 2 is reserved for asset loading and is skipped by the preloader).
Yet still, when I simulate a download I sit staring at a white screen until the entirety of my main class and the resources it uses have loaded.

Heck, I even got desperate enough to try having my preloader goToAndStop(4) after it finished (frame 4 is completely blank and there is no frame 5). The swf stayed the same size and the loading behaviour didn’t change.

So, I have only one question. What am I missing?

I also attempted, and got working, a multi-swf version. However, my submission medium only accepts single swf work, so unfortunately this option isn’t available to me.

I would, of course, be willing to provide any other information if it may be relevant.
Thank you for your help.