Customers jira site is treated as local intranet site in our office environment, this cause IE9 and IE8 all use "IE7 standards" mode ( another colleague reported another bug when viewing a dropdown selection list on IE8, which is also caused by IE8 using IE7 standards more).
"If there's no X-UA-Compatible value and site is in Local Intranet security zone, it will be rendered in EmulateIE7 mode by default."
The current workaround ( press F12, change it to IE9 standard for IE9 browser or IE8 standards for IE8 browser) only work for current IE instance, if I close all IE window and restart it again, I have to reset the browser mode for jira site again.
I think a new feature can be added to jira like:
if it found the client browser is IE8, send back header X-UA-Compatible to IE8;
if it found the client browser is IE9, send back header X-UA-Compatible to IE9.
IE7 mode in JIRA 4.4 has unpredictable behaviour as seen in the screenshot.