Hi Peter,
Thanks again, did everything you said - my input looks like this:
<p><img src="images/dkny%20sequin%20dress.png" border="0" style="border: 0; margin-left: 10px; margin-right: 10px; float: left;" /></p>
<p>Elke vrijdag shop je bij 'designer outlet heaven' the OUTNET de mooiste items uit één thema met 30% extra korting. Vandaag is dat 'The Downtown Look'. Hier vind je bijvoorbeeld dit geweldige feestjurkje van DKNY met gouden pailletten.</p>
<hr id="system-readmore" />
<p>Originele retailprijs € 345,-, bij the OUTNET voor € 155,-, vandaag dus voor maar € 108,50. Helemaal ge-wel-dig voor de feestdagen en Oud en Nieuw toch?? Wees er snel bij want voor je het weet is je maat uitverkocht...</p>

But still no image in the category view.... What can I be overlooking? Is it the template? Can it be..??
I really don't know...

Are you using a gantry framework template by any chance ? you can try assigning that category to another template temporarily see if it displays. Send a link and I will have a look if you want.

I'm using a template from Templaza - trekking fan. Could that be the problem then??

I just assigned the category I put the link fo the BEEZ 2 Template & it still displays the image, you have that template also I think, so if you temporarily assign that category to BEEZ 2 template you will see if it's your template causing the problem. What version Joomla do you have ?

I cannot assign 1 category to another template, I can (in K2) only choose DEFAULT....

I dont mean in K2, I mean in joomla, do you have link to your site ?