I had the same issue too. I’m not sure if this “fix” is universal, it may depend on the theme you’re using, but I did the following and now Disqus comments are working OK.
Log in to your Disqus account and go to the settings page for your site. Make sure that “Display login buttons with comment box” is NOT selected.
If it’s selected, I get no comments. If it’s not selected, I get comments.
It might be down to a CSS issue, either in my theme or with Disqus, as the Disqus comment area appears to be slightly wider than my theme. As of now I just haven’t had chance to examine the issue further.
Hope this helps!