DHCP through wireless router?

I have a small network consisting of a single Windows 2003 Server, three
wireless laptops, and three hard wired computers. the server is working
overtime running DNS, DHCP, file server, RIS, and Exchange 2003. Traffic on
my network is not a major issue and my server is loaded fairly well with
memory and handles the jobs well. I have a single broadband connection using
a cable modem. The cable modem is connected into a wireless router w/ 4 port
hub. All workstations and the server are connected via this router.
Anything hard wired directly into the router will pull an IP address from the
server, however the laptops using the wireless connection will not
successfully obtain an IP address. The wireless network is there and the
laptops see it, they just never receive an address. If I statically set up
the IP addresses, gateway, and DNS server adresses, all is well. Having the
static addresses is not that big of a deal, but to be honest I just do not
like not knowing why something is not working as it should and I would like
to figure this out. If anyone has an suggestions or is able to point out
something perhaps I have overlooked, your input would be greatly appreciated.