I used to use below to fix opera and ie8...

html:before, #wrap:before { /* Opera and IE8 "redraw" bug fix */
content:"";
float:left;
height:100%;
margin-top:-999em;
}

But it was brought to my attention that my demo no longer worked (wouldnt even display the page) in the newest chrome. I checked and html:before was the culprit. Changing it to body:before fixed chrome. But further testing showed that the newest Opera no longer even needed it. So now I just have the below code in my demo to fix opera and ie8 redraw bug...

#wrap:before { /* Opera and IE8 "redraw" bug fix */
content:"";
float:left;
height:100%;
margin-top:-999em;
}

Width:0 seems to work well too instead of margin-top:-999em. Although I seem to remember a reason for that.