If you want to have a preloader in your swf, but have a bunch of MovieClips that are set to Export for ActionScript, by default they export on the first frame. This makes the first frame take longer to load so you loader graphic or animation doesn’t show up for a while. If you uncheck “Export in frame 1″ in the MovieClip’s properties (this is only checked if it is set to Export for ActionScript) and take all the MovieClips that are exported for actionScript and drag them into frame 2, but out of view off the stage , the weight will now be on the second frame, which allows your loader on the first frame to show up right away.

Basically “Export in frame 1″ makes all the class and MovieClips available to ActionScript on frame 1, if you uncheck it, then you need to manually export those MovieClips by dragging them to the stage on the frame you want them to load in.

Here is a sample Try deleting the black box from frame 2 and you notice that the loader does not show up. But with the MovieClip in the timeline, the loader shows up.

A. Deselect “load on first frame”, then drag all the MovieClips that need to be loaded on the second frame of the timeline off stage. This way all the items will load on the second frame before all your code needs to access them.

I checked the source files and didn’t see anything on the 2nd frame..