ahh found it, apologies for not spotting it the first time.
In the sidebar, possibly a widget you have:
<h2 class="menuheader">Info</h2>
<div class="menucontent">
<ul>
<li>REAROK<a href="http://www.rearok.com" title="REAROK">
<a href="mailto:info@rearok.com" title="Rok Mele">Rok Mele <br />
BA (Hons) Media Production Management <br />
mobile: +386 40 881 624 <br />
e-mail: info@rearok.com <br />
Ljubljana, Slovenia <br />
<a href="mailto:info@rearok.com" title="Andrea Kršul">Andrea Kršul<br />
Academic sculptor<br />
mobile: +385 91 532 235 8 <br />
e-mail: info@rearok.com <br />
Rijeka, Croatia <br />
</ul>
</div>
That needs sorting out, as the link tags aren't being closed by a </a> which is causing the issue. (you are also missing end li </li>)