The Images are disappearing when you press F5 on the website but not with enter

I have a strange issue, and right now I'm more curious about the why than even how to fix it.

The images are disappearing when you click refresh or F5,

when you click to the link you may see or not the images (totally random)

BUT when you press enter or go on the url (depending on your browser) you will see the three of them,

the links:

http://belcorp.minonu.com/tips-y-consejos-para-promover-un-descanso-reparador/ http://belcorp.minonu.com/tips-tambien-recomendamos/

Any hints would be great! (the site is still not fully js and style optimized that's why you will see some styles and scripts not minified)

UPDATE ----- THIS IS HOW THE CODE LOOK ALL THREE OF THE IMAGES ARE THE SAME---

<div class="spb">
   <div class="demo">
   <img id="d1" src="<?php echo get_template_directory_uri(); ?>/images/f2.png" alt="Vainilla" onmouseover="_gaq.push(['_trackEvent', 'NOCTURNE', 'TIPS-AROMAS', 'VAINILLA']);" width="270px" height="270px" />
    <div class="bcol1 contenthover" style="background:#ebe5d8; color:#472035;">
    <h2>Vainilla</h2>
  <p>Su suave aroma produce un efecto balsámico contra la ansiedad, el cual consigue relajar a las personas más nerviosas.</p>

    </div>
    </div>

</div>

Solution

I don't know why it does or not work sometimes but you should add width="270px" height="270px", i tried it and it works all the time now