Async file uploads in Firefox reset on any DOM change

I'm pretty sure this is a Firefox or flash-related bug, but I just want to check if anyone has ran into this problem or knows how to fix it.

Basically, we have a multi-file upload widget for our highly dynamic web app (think Gmail). We've tried both uploadify for jQuery, and YUI uploader. We've also tried taking those out of our app interface and putting them in an iFrame. What happens is that in the event of any DOM manipulation, even if the uploader is in an iFrame, be it a tab change (in our web app) that covers the iframe temporarily, or a block, etc., the uploader will stop its current upload. In the case of YUI uploader, it fires the "contentReady" event again.

This ONLY happens in Firefox. IE and Chrome are fine. In case you are wondering, we really don't have any custom needs here. Just need to have multi-uplo开发者_如何学Pythonad file support, and we need to give people free reign to tab around in our interface while an upload is in progress. It seems like Yahoo! and Gmail have both solved this problem. How? What are we doing wrong?

I think it can by caused by firebug. Do you use it?

It's related to how Firefox handles a hidden Flash object. See this YUI bug http://yuilibrary.com/projects/yui2/ticket/2529235 A YUI developer explains what's going on when the YUI Uploader is hidden.