Some more test using :
- console.log($("div[style]").html());
Safari 4.0.4 - OS X : works fine
Firefox 3.6 - OS X : returns an empty string
IE8 - Windows : works fine
IE6 and IE7 - Windows : returns outerHTML (!)
Firefox 3.6 - Windows : works fine (??)
Sounds much deeper than I originally thought ;)