802.1q tagging

[Ayman Altounji]

I currently have a 6400r server that is functioning as a dhcp server on an isolated switch. The cisco switch has 5 different vlans on it and I want all of the clients on the vlans to be able to talk to the dhcp server. I dont want to have to use five different nics so thought of using one nic conection and the 802.1q tagging on the Compaq NC3122 Fast ethernet nic. However whenever I turn that feature on it cant talk to anything on the switch not even in its original vlan. Is there any issues with the 802.1q tagging on the compaq nic????
Thanks
moz3s