Typeahead.js interferes with Bootstrap input groups

Question

How do I keep Typeahead.js from splitting up my Twitter Bootstrap 3 input groups? Whenever I point the Typeahead javascript at a text area that's part of an input group, the joined text area and submit button stop being joined. Is this something that's just a bug in Typeahead, or is there a workaround for this?

Without loading Typeahead.JS:

With Typeahead.JS:

My original HTML:

    <div class="col-sm-4 hidden-xs">
    <form class="navbar-form" role="search">
        <div class="input-group">
        <input type="text" id="tags" class="form-control" name="q">
            <div class="input-group-btn">
                <button class="btn btn-default" type="submit">Search</button>
            </div>
        </div>
    </form> 
    </div>

This is what Typeahead does to this HTML:

<div class="col-sm-4 hidden-xs">
        <form class="navbar-form" role="search">
            <div class="input-group">
            <span class="twitter-typeahead" style="position: relative; display: inline-block;">
            <input type="text" class="form-control tt-hint" disabled="" autocomplete="off" spellcheck="false" style="position: absolute; top: 0px; left: 0px; border-color: transparent; box-shadow: none; background-attachment: scroll; background-clip: border-box; background-color: rgb(255, 255, 255); background-image: none; background-origin: padding-box; background-size: auto; background-position: 0% 0%; background-repeat: repeat repeat;">
            <input type="text" id="tags" class="form-control tt-input" name="q" autocomplete="off" spellcheck="false" dir="auto" style="position: relative; vertical-align: top; background-color: transparent;">
            <pre aria-hidden="true" style="position: absolute; visibility: hidden; white-space: nowrap; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; word-spacing: 0px; letter-spacing: 0px; text-indent: 0px; text-rendering: auto; text-transform: none;">
            </pre>
            <span class="tt-dropdown-menu" style="position: absolute; top: 100%; left: 0px; z-index: 100; display: none;"><div class="tt-dataset-0"></div>
            </span>
            </span>
                <div class="input-group-btn">
                    <button class="btn btn-default" type="submit">Search</button>
                </div>
            </div>
        </form> 
        </div>

Answer 1

 .twitter-typeahead{ float:left; width:100%} 

Answer 2

This project partially solved the issue for me: https://github.com/hyspace/typeahead.js-bootstrap3.less

The only outstanding problem is when I apply shadow effect to both the .btn and .form-control the shadow is drawn also between the input field and the button.