Error message when you try to delete a master page file from the "Master Page and Page Layout Gallery" in SharePoint Server 2007: "This item cannot be deleted because it is still referenced by other pages"

When you try to delete a master page file from the Master Page and Page Layout Gallery on the Site Settings page in Microsoft Office SharePoint Server 2007, you receive the following error message:This error message occurs even when the master page file is not associated with a SharePoint Server 2007 site.

To work around this problem, mark the master file as hidden so that the master file does not appear as a selection when you create a new site. To do this, follow these steps:

1. Use an account that has administrative permissions to log on to the Web application that is hosted on the SharePoint Server 2007 server.
2. Click Site Actions, click Site Settings, and then click Modify All Site Settings.
3. Under Galleries, click Master Page and Page Layout Gallery.
4. Click the list next to the master file that you want to hide, and then click Edit Properties.
5. On the list next to Content Type, click Page Layout.
6. Click to select the check box next to Hidden Page, and then click OK.
7. Click the list next to the master file, and then click Check In.
8. On the Check In page, select the options that you want, and then click OK.
9. Click the list next to the master file, and then click Publish a Major Version.
10. On the Publish a Major Version page, enter a comment, and then click OK.
11. Click the list next to the master file, and then click Approve/reject.
12. Next to Approval Status, click Approved, and then click OK to approve the changes.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.