IE navbar search problem

llo,
i added a searchfrom in my navbar and it widens teh height of my navbar its certainly the searchform cuas when i delete it everything is ok again.

I wondered if there’s any way to fix it.

The “header.php” code:

<div id="nav">
<ul class="nav">
<li class="first"><a href="<?php bloginfo('url'); ?>">Home</a></li>
<li class="second"><a href="https://hodiaudirekton.ipbfree.com/index.php">Forum</a></li>
<li class="third"><?php wp_list_pages('title_li='); ?></li>
<li class="forth"><?php include (TEMPLATEPATH . '/searchform.php'); ?></li>
</ul>
</div>

styles.css code:

#searchform{display:inline;height:20px;min-height:20px;width:100px;line-height:0px;margin:0;}
input#s{color:#ff0000;width:100px;border:0px solid #cbcbcb;background:#fff;margin:0 10px;}
input#searchsubmit{min-height:20px;height:20px;line-height:20px;background:#ff0000;color:#fff;font-size:13px;border: 0px;}

testsite url:
https://www.pulpflip.be/

can it ahve something to do with the “searchform.php” file?

<form method="get" id="searchform" action="<?php bloginfo('url'); ?>/">
<div><input type="text" value="<?php the_search_query(); ?>" name="s" id="s" />
<input type="submit" id="searchsubmit" value="Search" />
</div>
</form>
<br /><br />