Can not connect to the internet when LAN is enabled

I networked my computers using a router (being used as a hub only) and
a regular old hub. I am using a WIFI USB dongle by Kasens KS-G5000
with a RTL8187 chipset. When I am connected top the LAN I lose my
i9nternet connection in the network control panel under internet it
becomes disabled and I can not manually enable it. If I disable the
network connection I can then go out to the internet. What did I set
up wrong or is this what I have to live with?