Hi,
multiple authentication on hp procurve port with MAC-Based Auth works perfectly. You need to use hp-egress-vlanID, X times, you need to ste up dynamically a vlan on the port.
For example, i need vlan Tagged 176 and vlan Untagged 162 on a port,
my radius serveur send back
First client HP-Egress-VLANID += 838860962 U 162
HP-Egress-VLANID += 822083760 T 176
Second Client, especially a PC connected trhough ToIp port PC,
HP-Egress-VLANID += 838860962 U 162.
to help the procedure behave normaly, you have to plug on the ToIP, and start after your PC.
Emmanuel