In TWG I showed the iframes 200 ms after clicking to load the page in background. I had to change the implementation to make this work with IE 8 in all modes as well.
window.setTimeout(‘document.getElementById(“details”).style.visibility = “visible”‘,600);
does not work properly in IE8 while
document.getElementById(“details”).style.visibility = “visible”;
I have integrated this change already in TWG 1.7.7 and hope this helps anyone who runs into this problem.