Rosewill RNX-N300RT (TP-Link clone) and Client mode?

[thr33phas3]

After some flash gymnastics, I managed to get a Rosewill RNX-N300RT router (a clone of a TP-LINK TL-WR841ND v7.x) running Gargoyle 1.6.1. My intended use for it was as a wireless client near my media center, to give the various Ethernet-only devices there a chance to get on my home WLAN.

I set it up appropriately (I thought) to get on my existing WLAN:

Internet/WAN - Connect via: "DHCP (Wireless)"; Wan Ethernet Port: "Bridge To LAN"
Local Network/LAN - Router IP: something different from my existing WLAN (I used 192.168.1.1, because the existing WLAN is on 192.168.2.1)
Wireless - Wireless Mode "Client", and in the SSID to Join: section, scanned for and selected the SSID for my existing WLAN.

When I applied these settings and attempted to connect to the Internet via a wired connection, nothing worked - apparently no connection was made by the client running Gargoyle to the WLAN router, so no Internet or other connectivity was available (I couldn't even connect to the existing LAN's gateway at 192.168.2.1). However, changing the setting below as noted got it working:

Wireless - Wireless Mode "Client + AP", and set the appropriate settings that now appeared below for the Access Point.

Immediately, I was able to get Internet access from the computer with a wired connection to the Gargoyle client (I'm posting through it now, actually) as well as a wireless connection through the SSID that the new Gargoyle AP was providing for a tablet. I don't want to have the wireless connection available, though!

Why doesn't "Client" mode alone work as I expect (i.e. wired clients only, passing through the Rosewill unit to get on the WLAN, and nothing else)? Why must I have the AP running also? Has anyone else seen this?