What a disaster - images downloading multiple times

I have different images at various points in my movie, all of which are loaded with the following code:
[FONT=Courier New][LEFT][COLOR=#000000]var[/COLOR] myMCLoader:[COLOR=#0000ff]MovieClipLoader[/COLOR] = [COLOR=#000000]new[/COLOR] [COLOR=#0000ff]MovieClipLoader[/COLOR]COLOR=#000000[/COLOR];
myMCLoader.[COLOR=#0000ff]loadClip[/COLOR][COLOR=#000000]([/COLOR][COLOR=#ff0000]“images/myImage”[/COLOR], [COLOR=#0000ff]this[/COLOR][COLOR=#000000])[/COLOR];
[/LEFT]
[/FONT]
This is not working well because:

  1. The images do not download in the background until they are accessed on the timeline
  2. Flash attempts to download them every time they appear.

I thought Flash would download each image in the background just once and then that would be it.

The preloaders I make preload content and then show it immediately once it’s downloaded. How can I preload something and then use it later?

Also, if the user clicks the back button to return to the beginning of the timeline, the preloader kicks in again (it’s on frame 1) and downloads the image again! I want Flash to download stuff just once.
Someone please help.