hub is not the same as a router.
so might be different. i could only use my little hub when:
innernetz from modem, into my computer's in Ethernet port, out from my computer's out Ethernet port, into HUB.
Then my brother can plug his computer into the hub
then hes lamed up by half net speeds lol
if its actually a hub your using, and you actually got the net to work when the hub is directly plugged into the modem, then i am clueless, i didn't think the net COULD work like that. i always thought hubs were for when you had different ip options, or a proper server running a larger LAN. or whatever...