Still a problem with the latest version. The datepicker can also trigger the bug.Daniel wrote:update to the latest colorbox
I believe you can see the bug in IE tester (http://www.my-debugbar.com/wiki/IETester/HomePage) as that uses older versions of IE7 and IE8.
I have made a pull request that shows another way to workaround it. https://github.com/opencart/opencart/pull/248