Sound and NetStream bytesTotal is zero until the entire file is loaded in IE

The bytesTotal property only returns the total number of bytes after the sound or video file has completely loaded in both IE and Safari. However, in Firefox bytesTotal will return the total number of bytes in a sound or video file as soon as the file begins to load. Further the loadProgress, ProgressEvent.PROGRESS, event of the sound object does not fire as it should in Internet Explorer and Safari. Adobe makes no mention of this in their documentation! To show load progress in browsers other than Firefox the bytesTotal/getBytesTotal properties cannot always be used. You may need to have the total bytes loaded from XML or elsewhere.