I’m having a problem with the following code;
<li class="span4">
<div class="thumbnail">
<img src="" alt="" />
<div class="caption">
<h3>Title</h3>
<div class="clearfix">
<div class="pull-right">
<div class="btn-group">
<button class="btn btn-success"><i class="icon-thumbs-up"></i></button>
<button class="btn btn-danger"><i class="icon-thumbs-down"></i></button>
<button class="btn btn-warning"><i class="icon-star-empty"></i></button>
</div>
</div>
</div>
</div>
</div>
</li>
The buttons in the thumbnail description look like this;

The main problem I am having, is that these only appear broken sometimes. Not always.
It works fine in JSFiddle, but here it is anyway; http://jsfiddle.net/NsKYH/1/
May be it’s better if you define white-space:nowrap to
.btn-groupDIV. Write like this: