Actionscript 3 :: OSX's Quirky Scroll Effect Ruins Mousewheel Controls?

I'm building a web app to design and animate simple 3d scenes using the Away3D library, but the design of the interface itself is built around a scrolling menu which takes up the whole height of the screen.

The problem is, on OSX browsers have a silly quirk where if the page is scrolled when it has already gone as far as it can, the page can be dragged slightly further, revealing a brushed metal background. This looks nice and whatnot, but it pretty much ruins scrolling in a swf object. I use flash builder and export to safari, which is just about useable, if pretty annoying (especially with a mac touchpad, which can give a much higher scroll delta than a mousewheel can), but when I open my app in firefox/chrome the same effect happens, and causes the app and browser to slow down drastically.

I've found code which uses ExternalInterface to stop the swf sending mouse events to the page, but they all seem to disable detection in the swf as well, and I can't find anything else which help. If anyone knows of a solution you'll be saving me from throwing a few months' work away for what seems like a suspiciously unnecessary drawback to Flash on OSX!