Why is Google's Index Showing 404 Errors on Several Pages of my WPD site?

If you do a Google search for your site and see 404 errors on the results or when you click on any of the links, please read this.

This is probably happening because your sitemap is broken. To find out, go to www.mysite.com/sitemap.xml. Check the links on that page and make sure they are valid. If you notice that some or all of the URLs omit the category, you will need to change your sitemap plugin. For example:
Actual URL: www.mysite.com/birds/blue-jays-rule
Broken URL: www.mysite.com//blue-jays-rule
This error is known to be caused by a 3rd party plugin called Google XML Sitemaps by Arne Brachhold. We used to include this in our standard installation, but have since replaced it with our own, bug-free version.
To resolve this issue, you will need to uninstall your existing plugin and install one called Sitemap Plugin, which can be found on the Manage Plugins page of the WPD Control Panel. If you do not see an option to uninstall your existing sitemap plugin, please see:
How do I log into wp-admin?
We also strongly recommend that you sign up for a Google Webmaster Tools account. Please see:
Should I Sign Up for a Google Webmaster Tools Account?
Actual URL: www.mysite.com/birds/blue-jays-rule
Broken URL: www.mysite.com//blue-jays-rule
This error is known to be caused by a 3rd party plugin called Google XML Sitemaps by Arne Brachhold. We used to include this in our standard installation, but have since replaced it with our own, bug-free version.
To resolve this issue, you will need to uninstall your existing plugin and install one called Sitemap Plugin, which can be found on the Manage Plugins page of the WPD Control Panel. If you do not see an option to uninstall your existing sitemap plugin, please see:
How do I log into wp-admin?
We also strongly recommend that you sign up for a Google Webmaster Tools account. Please see:
Should I Sign Up for a Google Webmaster Tools Account?