http://www.matthewjrichards.co.uk/articles/2007/03/29/how-to-stop-ie6-background-flicker en-us 40 Freelance web developer and designer <p><img src="http://www.matthewjrichards.co.uk/files/screen_flicker.jpg" alt="Screen Flicker Image" /></p> <div class="update"> <h4>Update:</h4> <p>After an upgrade to Apache 2.2 (on Windows) this fix caused errors preventing Apache from starting. I have not had chance to investigate. USE AT YOUR OWN RISK</p> </div> <p>Whilst working on my latest project, <a href='http://www.thelearningbusiness.com'>a web portal for an e-learning environment</a>, I was presented with the issue of screen flicker in IE6 for elements using CSS to specify a background image.</p> <p>Whilst this may be annoying, irritating or just plain ugly to some. For others, particularily those with epilepsy, it could be potentially life threatening. </p> <p>Being a strong believer in the web being for everyone I set out to fix this issue. A quick google brought up some promising results. <a href="http://dean.edwards.name/my/flicker.html">Dean Edwards' blog</a> provided me with all the information I required whilst providing some humour based light entertainment at the same time.</p> <blockquote cite="http://dean.edwards.name/my/flicker.html">this is a browser problem not a server problem. Unfortunately the only way to fix it is by configuring your server.</blockquote><br /> <p>Luckily I'm a Linux kind-a-guy so setting up Apache took no more than a couple of minutes, a quick reboot of the server and everything was sorted.</p> <p>Dean also mentions in his blog that there's now a <a href="http://www.mister-pixel.com/#Content__state=is_that_simple">Javascript alternative</a>. However, I tried this solution with out success. </p> <p>So in summary, for those Apache users like me who want to prevent flickering in IE6 but can't be arsed to read the whole of this blog article.....</p> <p>Either add to or uncomment the following line to your httpd.conf</p> <code> LoadModule expires_module modules/mod_expires.so </code> <p>Then, in either your httpd.conf or a relevant .htaccess file add the following:</p> <ol class="codeblock"> <li>#this stops screen flicker in IE</li> <li>BrowserMatch "MSIE" brokenvary=1</li> <li>BrowserMatch "Mozilla/4.[0-9]{2}" brokenvary=1</li> <li>BrowserMatch "Opera" !brokenvary</li> <li>SetEnvIf brokenvary 1 force-no-vary</li> <li>&nbsp;</li> <li>ExpiresActive On</li> <li>ExpiresDefault A18000</li> <li>ExpiresByType image/gif A2592000</li> <li>ExpiresByType image/jpeg A2592000</li> <li>ExpiresByType image/png A2592000</li> </ol> <p>Restart Apache. Voila.</p> <p>If you're stuck with IIS, <a href="http://www.aspnetresources.com/blog/cache_control_extensions.aspx">check this out</a></p> Thu, 29 Mar 2007 10:42:00 +0000 urn:uuid:a542dd8d-f2bb-4dba-9f35-1522aaaf55ba mattr http://www.matthewjrichards.co.uk/articles/2007/03/29/how-to-stop-ie6-background-flicker ie6 flicker accessibility css howto http://www.matthewjrichards.co.uk/articles/trackback/6390