Columns-plugin: weird behavior on IE11

Changing columns margin/padding from -2em/2em to -1.5em/1.5em causes weird behavior on Windows 7/IE11. Tested on mac with VirtualBox, so don’t know if this is problem just with the VM.

Selecting page (with columns plugin active) from menu causes problem. Refreshing/manually changing browser width of the page fixes it (see gif)

Still haven’t figured out this. It seems that the site won’t load the main.css file properly and somehow completely ignores the border-box property until I change the width of the page or refresh the site. If I add the following part of the css straight to the header.php -file it works just fine:

  *, *:before, *:after {
    -webkit-box-sizing: border-box;
       -moz-box-sizing: border-box;
            box-sizing: border-box;

Any ideas why it does that?

Is that just a standard starterkit with the columns plugin and the css for the columns? With no changes whatsoever?

I tried it earlier with the standard starter kit. Just re-downloaded the whole thing and it works perfectly. Google analytics snippet seems to have messed up something on the other site I’ve been working on. Solved!