This collection already contains an address with scheme http.

http://www.chapleau.info/cs/blogs/fchapleau/archive/2009/09/12/this-collection-already-contains-an-address-with-scheme-http.aspx

Example

<system.serviceModel>
<serviceHostingEnvironment>
<baseAddressPrefixFilters>
        <add prefix=”http://payroll.myorg.com:8000”/>      
</baseAddressPrefixFilters>
</serviceHostingEnvironment>
</system.serviceModel>

http://blogs.msdn.com/b/rampo/archive/2008/02/11/how-can-wcf-support-multiple-iis-binding-specified-per-site.aspx