webclient 5.1 and linked mode

Hi

I have 3 in 5.1 in vcenter linked mode, one of the three component is installed on the same xed and always the webclient. When I try not login via web I get the error:

Client is not authenticated to VMware Inventory Service - https://xxxxxxxx:10443

And I can not see any web vcenter, while the client vsphere  everything is working properly

thanks

Fabio