Background Image Flicker Bug on Anchors

This bug affects Internet Explorer 6.0.

In Internet Explorer 6.0, background images applied to an anchor tag via CSS reload in the hover state or other dynamic state, creating a flicker effect. Some computers even experience this flicker on each hover or other dynamic event and at slower speeds, giving an even greater undisired effect.

This issue has been a problem on ABS for quite some time. ever since icon images were used as background images for links through CSS rather than the images being displayed using list-style in CSS.

Bug Fix

There are workarounds to this bug, such as placing the same images behind where the flicker occurs. However, there is a simpler method to fix the flicker behaviour.

The following lines must be added to your Apache server's .htaccess file:

#this stops screen flicker in IE
BrowserMatch "MSIE" brokenvary=1
BrowserMatch "Mozilla/4.[0-9]{2}" brokenvary=1
BrowserMatch "Opera" !brokenvary
SetEnvIf brokenvary 1 force-no-vary

I have tested it and it does not fix the issue on all computers, but am noticing no more than one flicker on this current computer running Windows XP SP1.

Thanks to Dean Edwards for the .htaccess code.