When you add Disqus to your site e.g. as I did with http://www.lincolnphipps.org then make sure that the following Disqus plugin advanced option is set,
If it is not checked then when you click the post and then click the (theme dependant) link that is usually at the top of a post to jump to the comments at the bottom of the post, it does nothing. The default WordPress anchor tag is #comments but with Disqus it is #disqus_thread
When this disqus plugin advanced option is checked then the correct anchor is used and you will jump to the Disqus comments as expected.