This is an archived snapshot of W3C's public bugzilla bug tracker, decommissioned in April 2019. Please see the home page for more details.
http://lists.w3.org/Archives/Public/www-style/2011Apr/0805.html
The issue that the visible/hidden rule was backwards was fixed in http://lists.w3.org/Archives/Public/public-css-commits/2011Jul/0120.html but this still needs to be fixed to describe animations between collapse and other values.
Fixed in http://dvcs.w3.org/hg/csswg/rev/bf3f36be697c