The current version of WooCommerce and Disqus are not playing well together. When activated, Disqus attempts to replace the product reviews and fails. When using both plugins the reviews are non-functional.

I've handed it on my site by modifying disqus.php with a conditional check to return blank if the page is a single product. I'm sure there is a more update-friendly way to handle this, but I figured it would be better just to let you guys know about it.