Sorry, this is incorrect. The HTML5 doctype is backwards compatible and therefore supported by all browsers. If you just changed the doctype (and didn't add any HTML5 semantic elements) then you must have a problem in your actual HTML code that was being 'corrected' (or corrected to your eye) in quirks mode in IE. Post your code, or preferably a link. Also, run it through the w3c validator and fix any non-trivial errors and you should be fine.
Originally Posted by danielshill
Note that not all browsers properly support the semantic elements and can and will display them differently (without the appropriate polyfills) but no browser will barf simply by showing it an HTML5 doctype.
I've switched careers...
I'm NO LONGER a scientist,
but now a web developer...