The JS error still present in IE8 (even in standards mode) is caused by animation. Somehow after a bunch of animation calculations a negative height is being set in IE8, which triggers the error. There is a comment in the code which says, "IE gets very inconsistent results when animating elements". In Firebug we can see a strange number involved in the calculation: -0.4333999999999989. So this is likely caused by some freak calculation and/or rounding errors in this particular layout scenario.

Can we modify the JS for the animation to trap the negative height and set it to zero instead then?

Done and tested.

Modified: C:\svn\ossrepo\icefaces3\trunk\icefaces\ace\component\resources\icefaces.ace\jquery\ui\jquery-ui.js
Completed: At revision: 26652

Tested ace:accordion component using code revision 26767 with IE8 .

There are no more JS errors, however the accordion inside ace:tabSet does not work properly: if switching to the closed panes, the accordion collapses altogether and panes cannot be open afterwards.
This issue occurs in IE 8 and Chrome 15 (not in Firefox).

Unsure if this issue is related to the fix for the JS errors in IE8 (this JIRA), or to the fix for the 'collapsible' attribute (ICE-7497).

Note: The accordion component on the test page was defined with collapsible="false".

To reproduce:

• test application location: http://server.ice:8888/svn/repo/qa/trunk/Regression-Icefaces2/Sparkle/Nightly/accordion
• load the test page for accordion isnide ace:tabSet: http://localhost:8080/accordion/accordionIceTabSet.jsf
• page opens with first pane open. Click on the next pane to open -> this works fine.
• click on the third pane -> this collapses all accordionPanes.

Created ICE-7546 for the ace:accordion inside ace:tabSet issue described above, and closing this as per Ken's request.