Zi, you can customize the template chunk however you want, but there are a couple of things needed for it to function correctly. I have the template split into three parts using the <hr> tags, these are removed for the final output, but need to be in your chunk. The format for the template should look like the following:
Header markup
<hr>
Markup repeated for each file (including placeholders)
<hr>
Footer Markup
So if you change your template to this it should work:
<div class="downloads">
<hr>
<div class="file">
<a class="dload-img" href="[+link+]" title="Download [+filename+]">
<img class="dload-img" src="assets/images/download.png" alt="Click to download template files." />
</a>
<br />
<strong>Size:</strong> [+sizetext+]<br />
<strong>Downloads:</strong> [+counter+]
</div>
<hr>
</div>
Let me know if that makes sense and fixes your problem.
Kyle