Full description: http://groups.google.com/group/jquery-dev/browse_thread/thread/f46d8dddfdf5eefc

Short description:

When animating, for example sliding down an element (foo) inside an container (bar) with an explicit width, jquery doesnt take the width in to account when calculating the height of foo when its hidden. This could lead to jquery calculating the wrong height of foo if the width of bar makes text in foo linebreak like in the example in the full description url. It might sound vague but looking at the url above and the screenshots makes it a little more clear.

Suggested solution: When the position:absolute and visibillity: hidden is applied to the hidden element to determine its height an explicit width should be added calculated from its implicit width, once the correct height is determined, the explicit width can be removed.

As mentioned on the dev mailinglist Im not aware or sure about what kind of sideeffects a change like this could lead to, so i guess someone with good insight should say something about this first.