I’ve been trying the starter, this bug I believe is still unfixed or reappeared.
Good news is when trying nightly build of ionic bundle using:
<link href="//code.ionicframework.com/nightly/css/ionic.css" rel="stylesheet">
<script src="//code.ionicframework.com/nightly/js/ionic.bundle.js">
The Ionic-starter-sidemenu will run as expected.
Though if I use ionic.bundle.js v1.0.1, bug will show.
There is also a post Sidemenu seed project drops back button during navigation talking about this. It seems a fix is already made, but reapeared on 1.0.1.