Hey bubbajoe, a few questions:

General Networking Questions:
Do devices with 192.168.2.x addresses have access to Samba Ok?
Why do you have the wireless router issuing IP's on 192.168.3.x?

General Networking Comment:
I'm not sure what the 192.168.2.x router is doing for you that the ISP router is not doing... So what is it's purpose?
I'm also not sure why you have the wireless router doing DHCP? You may want to see if it can behaving in "Access Point" mode. If your wireless can't act as an AP, perhaps use it to replace the 192.168.2.x router and eliminate one level?

Samba comments:
You'll only be broadcasting on 192.168.2.x... so try browsing by IP, like \\192.168.2.12 (if that's the POPO IP).
Also, try just "hosts allow = 192.168." - that should just cover all your IP's.

Lee Jones

You could do a repeater/bridge, but generally those would stay on the same subnet (they would both be 192.168.2.x).

I take it that devices that are 192.168.2.x are OK? Just the 3.x devices do not work? I'm curious if your 2.x devices can ping the 3.x devices. You may have a TCP/IP problem instead of a Samba problem.

Lee Jones