So we have a cable modem. Connected to the cable modem is a linksys router. Connected to the router is a hub, and also a wireless router that is pretending to be a switch (the cable from the router is plugged into a network port, not the wan port).
If you plug a cable from the hub into the wireless router, the network explodes!!
Whaddaya know.
Note to self: perhaps it's time to untangle and label the cables, hmm?