Problem width div

Hi everyone, I have a question about a simple responsive design with div’s which are floating to the left when resizing the screen. This is my code in html:

<div class="homewrapper">
<a href="/#">
<div class="figure"><img src="/#" alt="test" width="285" height="185" /></div>
<div class="homecat-underblock">
<h4>Test</h4>
</div></a></div>

The problem is when i resize the screen the homecat-underblock is smaller than the homecat-block.

It must be something very simple, but I dont see it for the moment…

Some help will be appreciated…