When I enter a particular URL in my link submission form and click 'Fetch Info', I receive the error 'Could not load the page at URL'.

A small minority of web pages are configured to disallow access by automated scripts such as LinkMachine. To determine whether the page containing the reciprocal link cannot be viewed by LinkMachine for this reason, go to this page:

http://linkmachine.net/fopen_test.php

Enter the URL of the page and click Load Page. If the page does not appear, then LinkMachine is not being allowed to view that page. You should still be able to enter the site's info manually, but LinkMachine will not be able to check for a reciprocal link at that site so its status should be set to One way link.