First of all, no. Having 2 dhcp servers on one physical segment is almost certain to cause problems. You'd probably be able to get it to work some of the time, probably depending upon the order in which you turned stuff on, but it's still a bad idea.
HOWEVER...
what else is connected to that 8 port hub? If all that's connected is your modem and your AP, then it's completely extraneous. All you need to connect the two devices is a straight through cable, which is probably what you've got going from your Hub to your AP and modem anyways, though I suppose they could be crossover, and possibly still work. If your cables aren't physically long enough, then you could probably head to a local computer shop and get them to make one for you for a much better price than you'll find at Best Buy or RadioShack or any other electronics stores. As long as the total length of the cable is less than 100 meters (that's 328 feet), you've absolutely no reason to be using a hub there.
It's also possible that you need a crossover cable between the modem and the AP, but that's less common, and varies by modem manufacturer.
A quick way to check a cable is to hold both ends of the cable next to eachother, and look at the connectors the same way (i.e. bottom of both, or top of both) and look at the color of the wires... if they look the same, it's straightthrough, if some of the wires are switched, it's a crossover.
