Exception while trying to add an End Point to traffic manager

Hi 

Getting an exception while trying to add an endpoint using powershell to an existing ATM profile. This works fine when using the portal to add the same end point

Get-AzureTrafficManagerProfile -Name "test" | Add-AzureTrafficManagerEndpoint -DomainName "test.cloudapp.net" -Type CloudService -Status Enabled | Set-AzureTrafficManagerProfile

Set-AzureTrafficManagerProfile : BadRequest: A frontend exception detail was generated with an error code of 
BadRequest_LocalizedStringFormatFailed, which was not defined in the shared library. The resource library should be updated in both the 
shared library and the client. Until that happens, the client will see a 'generic' error message that mentions the undefined error code 
and invites them to contact Microsoft Customer Support.
At line:2 char:162
+ ... atus Enabled | Set-AzureTrafficManagerProfile
+                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : CloseError: (:) [Set-AzureTrafficManagerProfile], CloudException
    + FullyQualifiedErrorId : Microsoft.WindowsAzure.Commands.TrafficManager.Profile.SetAzureTrafficManagerProfile

Any help is appreciated! Thanks!