Issue

In timed tests or surveys containing lots of questions displayed all at once, users of Microsoft Internet Explorer 7 report very slow scrolling behavior and even browser lockups. This will often lead to students having to go overtime to complete the quiz. In other instances the "submit" button is obscured

Cause

Internet Explorer 6 and earlier do not by themselves properly redraw the floating DIV element used for the timer when scrolling, and require a workaround implemented in JavaScript (fixed.js) to correctly redraw all fixed-position screen elements after scrolling. This method incorporates a delay to give the application time for a full redraw before calling the redraw function again. Now the screen redrawing behavior and CSS support of IE have changed between versions 6 and 7, and something in fixed.js is causing IE7 to choke under certain circumstances that we have not been able to fully identify.

Resolution

A full fix of the issue is in release 9.0, which no longer employs fixed.js at all and has a newly redone timer.

Clients running affected releases can download the attached new replacement script fixed.js and place it into blackboard/webapps/assessment/.

End users will have to clear their browser cache to reload this script and may need to completely restart the browser as well (due to weaknesses in IE's cache handling).