How can I get my network set up the way I want?

[Fryguy]

I have a gateway/modem that does NAT routing. Along with the gateway, which is assigned an IP, I also have 5 static IPs. The problem is, I assign static IPs to a couple of key computers on the network, and NAT the rest (mostly my wireless connections through a wireless switch used as an access point only, no connection to the wan port, and dhcp turned off). Computers with static IPs can talk to each other, but computers that get an IP from dhcp can't.

How can I fix this, short of using something like hamachi? It seems like I should be able to do this routing in hardware easily, but I can't figure it out.

Here is a pic of my current setup:

http://fryguy.nevercontent.com/mycurrentnetwork.jpg