External swf is imported as AVM1Movie on one computer, causing problems, whereas same code imports same swf as MovieClip on other computers

I have a bunch of AS3 swfs. They are imported into an AS3 application using a Loader. On 10 or so different computers these AS3 swfs are imported as MovieClips and I can control them as necessary. However, on one computer no matter what I try (casting loader.content as MovieClip, remaking 开发者_如何学Pythonthe AS3 swfs from scratch) they are always imported as AVM1Movies.

All computers including the one that doesn't work are running Flash Player 10.

Is there something I'm missing or haven't tried?

Unistall Flash - reinstall Flash.

This does not sound like a flash bug but a computer bug. I think having 9 computers work and 1 computer not work (obviously this computer is the managers) means it should not be your code.

There is no way for an AS3 SWF to be loaded as an AVM1Movie. It's not possible. Check the SWF being loaded on that system.