I'm trying to use the affix plugin by twitter bootstrap but I can't figure out how to constrain it within the parent container, i've created the following example to show my problem:
Problem demo: http://www.codeply.com/go/DvcRXkeFZa
<div class="container">
    <div class="row">
        <div class="col-md-3 column">
            <ul id="sidebar" class="well nav nav-stacked" data-spy="affix" data-offset-top="130">
                <li><a href="#software"><b>Software</b></a></li>
                <li><a href="#features">Features</a></li>
                <li><a href="#benefits">Benefits</a></li>
                <li><a href="#costs">Costs</a></li>
            </ul>
        </div>
        <div class="col-md-9 column">
            <h1>Blah, blah, blah</h1>
            <hr>
            <a class="anchor3" id="top" name="software"></a>
            <p>
             content here that scrolls...
            </p>
        </div>
    </div>
</div>
As you can see when you scroll it overflows out of the sidebar, it also doesn't affix to the bottom of the page when it reaches the bottom.
 
     
     
     
    