I have two Alfresco installs running - 1) 4.0.d and 2) 4.2.c
From Windows 7 and Mac OS X clients I can connect to //alfrescoip:8080/alfresco/webdav and //alfresco40d:7070/alfresco I cannot connect to 4.2.d via WebDAV from any address. Catalina.out and alfresco.log show no errors at all.
Not sure how to explain this, but it's working as expected now.
I did nothing to the configuration except: - this server lives in a virtual machine - I did a proper shutdown of Alfresco and the Ubuntu install inside the virtual machine to save resources for other VMs. - Started it up this morning. Voila. It works.
If I figure out how that simply fixed the problem I'll post it here.