Why is my router assigning the wrong address via DHCP

Are you sure there isn't a second DHCP server on the network?

I had a similar issue. I had plugged in my Vonage adapter to my router using the "PC" connection instead of the "WAN" connection. The "PC" connection was acting as a DHCP server on the network and assigning IP requests to devices, even to devices that were connecting via the Router's wifi connection! How crazy is that?

Is your router setup for two different subnets?

You can 1) Check the subnet mask or 2) Just plug another device into the same physical port where you plugged your MacBook and see if it's also 192.168.29.*