First : add to your web.xml like this
<context-param>
<param-name>org.richfaces.enableControlSkinningClasses</param-name>
<param-value>true</param-value>
</context-param>
Then add css here to tag style
<h:outputStylesheet>
.rf-pp-shade{
position: absolute;
width:2000px;
height:1000px;
}
</h:outputStylesheet>
At rich:popupPanel tag , you need add more attributes like this
shadeClass="rf-pp-shade" style="position:absolute"
And that is popup will run on IE 6
I hope this helpful for you and sorry about my bad English.
Thanks Nguyen Nguyen for your answer but the popup continues working wrong. Probably it's a bug in richfaces 4.0 because i tried the popup pannel in 3.0 version and this issue doesn't produce.
I hope to find the solution to this problem.