Ok, you have a few problems. The WRT610N is a router. It's not a simple access point- which is what you should use instead. That device is used just as you are using your ASA firewall. You probably shouldn't really have 2 firewall/routers on the same network. I'll just assume that you want to keep it.
I'm assuming that your WRT610N LAN IP is 192.168.1.23. If the internet IP of the WRT610N is 192.168.1.23, then remove that. You would go into the management page of the WRT610N, probably by going to (
http://192.168.1.23). You should have no IP for the WAN/internet interface. But make sure to change to another IP first so that you don't lose the ability to configure it.
Then turn off the DHCP server from it. That way, the WRT610N won't give out ANY ips. Then you wouldn't use the "internet" port on the back of the WRT610N. The WRT610N probably has 4-5 "LAN" ports and 1 internet port. You would need to just connect your LAN Switch to one of the "LAN" ports on the back of the WRT610N.
Ensure that no other devices have the same IP as the wireless router on your local LAN.
To summarize, this is what you need:
-Only connect 1 LAN port of your WRT610N to the local lan
-Give the WRT610N a static IP for it's LAN interface that doesn't interfere with any other IP
-Make sure the WRT610N is not giving out any DHCP
With that setup, a machine will connect to the WRT610N and ask for an IP. The machine will get the IP from your ASA or other DHCP server and then will be able to get to the web through the ASA and access any systems on the local lan.
