I'm using Browserlabs to compare a web page in various browsers. I'm finding that the rendering is inaccurate enough that the tool isn't worth the time, since it renders inconsistent results. Especially when you have a div > ul > li > a html element setup. I've seen a set of LIs render incorrectly several times today.
Just now, I switched to IE 9 in browserlabs and the page that's rendered has LIs with their class rendered as text (so it says "menu Home" instead of "Home").
A few minutes ago when i viewed a page in Chrome 18 in browserlabs there were LIs that didn't have style information and were in the wrong part of the page because of it. When I viewed them in the real browser they did not look that way.
All in all, my first half hour of browserlabs makes me think that I wasted half an hour.
It looks to me like browserlab is only loading part of the css. I guess I don't have a real question here, unless it's "why is this sucking so hard?"
Edit: I'm also seeing instances where I change browsers (from Chrome 18 to IE9) and the viewport is black.
I'm using FF 13 and Flash 11.1 (just updated this AM).