Cannot recreate EWS Virtual Directory in IIS

I've been working through the seemingly very common issue of not being able to access the Out Of Office feature in Exchange 2010 using Outlook 2010 from external locations, or from OWA.

Used Fazal's response in this thread http://social.technet.microsoft.com/Forums/en-US/exchange2010/thread/b5026be0-c7ef-4fc2-878c-cd80f2ee26c8 to delete and recreate the EWS directory.

Now, after completing the procedure as described by Fazal:

I have no EWS virtual directory showing in IIS, EMC command Get-WebServiceVirutalDirectory | Format-List returns nothing, and re-running New-WebservicesVirtualDirectory returns:

"An error occurred while creating the IIS virtual directory 'IIS://SVR2.terotek.co.nz/W3SVC/1/ROOT/EWS' on 'SVR2'.
    + CategoryInfo          : InvalidOperation: (SVR2\EWS (Default Web Site):ADObjectId) [New-WebServicesVirtualDirectory], InvalidOperationException
    + FullyQualifiedErrorId : 52BD170,Microsoft.Exchange.Management.SystemConfigurationTasks.NewWebServicesVirtualDirectory"

OWA is now not working.

Any help greatly appreciated.