Usually the bottom ad-banner, by the looks of it. The entire browser tab is completely unresponsive until the ad has finished loading/rendering. IE11/Win8.1.
Wasn't like this yesterday; has something changed overnight? Or maybe I'm the only one seeing this...
The ad code should load asynchronously, so you shouldn't have to wait for the ad to finish loading before you see the page. I'll do some testing this week.
@Rys The issue seems to have fixed itself overnight, whatever it was... I haven't seen the same behavior for days now, thankfully, so unless you or another behind-the-scenes B3D staffer did anything to cause it or fix it then it must have been some random fluke... Thanks anyway.