Hey,
I was able to reproduce your problem, it didn't occur until I updated my Chrome version though (I'm on a PC).
To solve this go in your style.css and remove the padding line from #main{ /*main area, contains all content and sidebars*/.
Now in the same file add a margin to .content right below the previous edit, like this:
.content{
width:620px;
padding-right: 20px;
float:left;
margin-top:20px;
}
Also, in the same file add a top margin to .sidebar, it should look somewhat like this:
.sidebar {
float: left;
margin-top: 20px;
padding: 0 0 20px 0;
position: relative;
width: 300px;
}
This solves the issue, I'll contact Kriesi about this.