Wireless and dhcp

I have network that's running ad, dc and since recently dhcp on win2003.
Recently we implemented ISA for testing purposes,and also our LAN clients
were getting IPs from dhcp on linux, but we set up dhcp on win also.
everything works fine except for one thing - we have 5 AP and all of them use
to work (prior to above described changes) and now only one works (Linksys
wrv54g). Other APs are configured with static addresses, we tryed enabling
and disabling dhcp on them, but every time a client connects - he gets
message "limited or no connectivity" - he doesn't get ip address. So, I'm not
sure what we are doing wrong, but any help would be appreciated. Should this
work by default - client sees wireless, connects trough AP, "reaches" server
on which DHCP is running and gets its ip? APs we used are D-link
DWL-2000AP+..