Twitter Bootstrap drop down menu not working

Question

I know there are a lot of questions like this on Stack Overflow and I've looked at them but my dropdown menu still isn't working.

Here's my code:

<div class="navbar navbar-inverse navbar-fixed-top">
                <div class="navbar-inner">
                        <div class="container">
<ul class="nav pull-left">
<li><a href="#myModal" class="dropdown-toggle" data-toggle="modal" data-keyboard="false" data-backdrop="static">Login</a></li>
 <li class="dropdown" id="accountmenu">
                        <a class="dropdown-toggle" data-toggle="dropdown" href="#">My Account<b class="caret"></b></a>
                        <ul class="dropdown-menu">
                            <li><a href="#">Login</a></li>
                            <li><a href="#">Register</a></li>
                        </ul>
                    </li>
                        </div>
                </div>
</div>

What's wrong with it?

EDIT

So the drop down menu is now working with the answer posted to this question. However if I include the scripts mentioned over there the modal window stops working. And when I comment those entries it starts working again.

Here's the code for my modal window:

<div class="modal hide" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel"
    aria-hidden="true">
    <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-hidden="true">
            X</button>
        <h3 id="myModalLabel">
            Enter your Credentials</h3>
    </div>
    <div class="modal-body">
        <form class="form-horizontal">
    <div class="control-group">
    <label class="control-label" for="inputEmail">Email</label>
    <div class="controls">
    <input type="email" id="inputEmail" placeholder="Email">
    </div>
    </div>
    <div class="control-group">
    <label class="control-label" for="inputPassword">Password</label>
 </div>
    </div>
    <div class="control-group">
    <div class="controls">
    <label class="checkbox">
    <input type="checkbox"> Remember me
    </label>
    <a href="news.php" class="btn btn-primary">Login</a>
    <a href="registration.php" class="btn btn-primary">Sign up</a>
    </div>
    </div>
    </form>
    </div>
</div>

And the JavaScript for the trigger:

$('#myModal').on('hide',function(){
    $('.nav > li > a.modal-open-li').removeClass('modal-open-li');
});

Answer 1

For anyone still experiencing this problem. I found that I was including the bootstrap js files twice (I had split my header, body and footer files and had not realised I was including them both in the footer and header.

Might help someone.