Recently, we tried creating a secondary Isolated Host to separate receive and send processing for WCF. After reconfiguring the servers, we were faced with the “Receive location for address ” not found. (The BizTalk receive location may be disabled)”. Puzzled, we looked around for configuration issues. After some reading (http://technet.microsoft.com/en-us/library/aa559328.aspx), we remembered a new isolated host needs a new application pool. Adding another application pool to the mix the the new host fixed our trouble…
Jotted down for posterity 😉