said by Balla :I agree with CptGemini and have had personal experience with this.
I have the same Linksys 3000 install behind the ubee. I left the Ubee in NAT mode like when they installed it. The linksys needs to be set for dhcp and the linksys WAN should be plugged into a port on the Ubee. So my linksys WAN grabbed a 192.168.0.3 external address. And interally (through linksys wireless) its handing out 192.168.1.x addresses. On the Ubee I then made 192.168.0.3(WAN IP for Linksys) in the dmz so it will pass traffic to it. Or you can port forward all ports to the 192.168.0.3.
This has worked well for me so far besides having a pc plugged into the Ubee switch and not being able to the the 192.168.1.x network. But through the linksys you can access both 192.168.1.x and 192.168.0.x networks.