Iis – Unable to delete web site in IIS 6

I have IIS 6 running on Windows Server 2003 SP2 with several web sites running. I'm in the process of cleaning up the server. There is one web site in particular I cannot delete:

• I have stopped the web site
• When I right-click the web site in IIS to bring up the context menu, "delete" is missing (unlike other sites running on this server)
• If I select the site in IIS and press the delete key, nothing happens

Any ideas what might be causing this and what I can do to remedy?