Take the 2-minute tour ×  I came across a very interesting issue
in IE9. When using filter: alpha(opacity=) or -ms-filter css
property on a wrapping div the box model of the inner block
elements get corrupted. In other words the collapsing of
vertical-margin gets disabled and vertical-margin is added
instead. I'm facing this issue only in IE9. IE7/8 is not
affected.  Here's a jsFiddle with the isolated issue. Use the
trigger anchor to activate the class that includes filter: alpha
on the wrapping div. (IE9 only)  Any ideas why this is
happening?  Thanks in advance  share|improve this question Any
filter seems to do this ( jsfiddle.net/7BFd7 ). But, the CSS
property opacity works in IE9, and doesn't cause the glitch. So,
using the filter only in an [if lt IE 9] commented style could
be a work around. –  Roman Sep 17 '12 at 16:16 Thanks for the
quick reply. I already thought about this since I'm using
boilerplate in all of my projects. However this behavior is
indeed very odd... –  travisbotello Sep 17 '12 at 1