If I do an action that loads a dialog box (the in-web-page kind) then it keeps loading more and more on top of it. The nice shadow it has gets darker and darker. Any attempt to type leads to the characters individually go into separate boxes as newer ones load on top. Clicks that only change the dialog itself are futile since another box loads on top immediately thereafter. I've done this on the "add an email address for yourself" page and on the "add multi-factor authentication" page. The "loading" icon (a compass but rotating?) shows up in the bottom-right hand corner of the page and stays there as everything grinds to a halt.
So, what's my browser? "Iceape 2.7.12.". What? That's a rebadged Mozilla Seamonkey because Mozilla decided Debian can't keep using the trademarked name and the rights to patch the source at the same time. Yeah, but Seamonkey? That's the browser Mozilla used to ship before it decided to break it apart into standalone components such as Firefox for web browsing and Thunderbird for mail. But they still maintain Seamonkey for those of us who won't let go of our Netscape 4 UI. So it's the same HTML, CSS, JS and network stack as Firefox 10.0.11, but with a fun user agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.12) Gecko/20130823 Firefox/10.0.11esrpre Iceape/2.7.12
Oh, but there's one truly amazing aspect to my browsing experience you may need to replicate the problem: things in my prefs.js. Your javascript can get but not set Window properties "innerHeight", "innerWidth", "outerHeight", "outerWidth", "pageXOffset", "pageYOffset", "screenX" and "screenY". Completely forbidden are Window "resizeBy", "resizeTo", "scroll", "scrollBy", "scrollTo" and "sizeToContent". If you use a Mozilla browser, you can replicate this by pasting this: http://pastebin.com/Pg6sMvr9 into your prefs.js while the browser is not running.