I've had LinkMachine check for reciprocal links, and there's one site that definitely does have a link back to my site, but LinkMachine set its status to Link-back missing anyway. Why isn't LinkMachine recognizing this reciprocal link?

There are a number of possibilities:

1) LinkMachine checks each site for its reciprocal link on the page specified by the Reciprocal Link URL for that site. Does that URL point to the page where the reciprocal link is placed?

2) Is the reciprocal link valid? Does it contain your site's URL as you specified it in LinkMachine's Site Settings, and is it spelled correctly?

3) Is the reciprocal link a direct link to your site? Right click on the reciprocal link and choose Properties. If the link is indirect - for instance if it points to a script on that other site rather than directly to your site, then LinkMachine has no way of recognizing this as a link to your site. (Neither do the search engines, so this link will not help your search rankings either). If you'd like to continue to link to this site, you can set the site's status to One way link.

4) If the reciprocal link is in a frame or an iframe, try setting the Reciprocal Link URL for that site to the address of that frame itself, not the address of the frameset that it is within.

5) LinkMachine does not count links as being valid if they include the rel="nofollow" attribute. This is because search engine spiders do not follow links that have that attribute, so such a link is useless to your site for SEO purposes. Some shady webmasters use this trick to get other webmasters to link to their site without providing a valid reciprocal link in return. Check the source of the page containing your reciprocal link to make sure the link does not conatin this attribute.

6) Finally, some 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; enter the URL of the page with the reciprocal link and click Load Page. If the page with the reciprocal link does not appear, then LinkMachine is not being allowed to view that page. You could contact the webmaster of that site to try to resolve the problem, or set the site's status to One way link so that LinkMachine will not check it for a reciprocal link.