We are installing a new IP 900 for a customer and they have Cisco switches they are using vlan 134 for the data vlan and 136 for voice. We have set the vlan 136 in f821. The phone will just hang and not connect to the system. The only way it will work is if we change the data vlan to 1 then the phone will connect to the system and the pc will connect to vlan 1. Any ideas why we cannot use vlan 134 for the data vlan and why only vlan 1 will work??