Dhcrelay problem on pfsense 2.0 beta5

[pmbm]

Hi

I have the following problem on dhcrelay configuration on pfsense 2.0 when i start the service, the next message is returned " dhcrelay: Can't attach interface UGS to bpf device /dev/bpf0: Device not configured"

I search for a solution and a found something that sugests to change the kernel config file and then build the kernel.

Anyone have already get this problem or any other sugestion to solve this .

thanks in advance.