When using importFileInto or set the fileName of member to import external media in to a movie that plays in a browser, use preLoadNetThing "http://URL.myGif.gif" before importing the file. Wait for netError() to return OK and netDone() to return TRUE before executing the importFileInto command or setting the fileName of member property.

It is highly recommended doing this on a sequence of frame behaviors, which gives the operation time to execute and return status information (such as TRUE, FALSE or a netError number)."

For an example of this technique, see the the sample file in TechNote 14595