Preloader messages never go away/stay sometimes

[GoogleCodeExporter]

On Opera, the messages for audio preloader elements don't update their progress 
bars or disappear. This is likely caused by missing or faulty (for example not 
firing at all if the file loads too fast) implementation of the progress event 
for audio tracks.

W3Schools reports all browsers being capable of using the event.

Original issue reported on code.google.com by [email protected] on 22 Jun 2012 at 2:41