I think your browser is probably choking on the MathJax on the Mathematics website. This occurs for me in Cross-validated from time to time -- especially if I load the page and then click on to another stack-exchange site before [cv] has finished loading.
The source in questions for the 'add comment' and 'edit' links is easily examined -> Firefox has a 'view selection source' which I think chrome has too? not sure? Anyways, the source is:
<div class="post-menu"><a href="/q/97613/152009" title="short permalink to this question" id="link-post-97613">link</a><span class="lsep">|</span><a href="/posts/97613/edit" title="edit this post">edit</a><span class="lsep">|</span><a id="flag-post-97613" title="flag this post for serious problems or moderator attention">flag</a></div>
As this is quite standard html, I doubt your browser is choking on it. It could be a serving issue -- I know nothing of the backend implementation, but again, I doubt these links are the issue. It's probably Mathjax.