Linksys Wireless Router :: Guest Access Breaks If E1200 Set Up As Bridged Wireless

I want to set up an E1200 as a wireless access point for guests, and ordinarily I'd be happy to connect it LAN-to-WAN and have it create its own subnet, but I need to connect one office PC to it also because connecting the E1200 to the main gateway displaces that office PC from the last Ethernet port on the main router.
 
So I disabled DHCP on the E1200 and connected it LAN-to-LAN.  The modem is at a fixed, non-configurable address of 192.168.0.1/255.255.0.0 and the main router is at 10.0.0.1/255.255.255.0.   I set the E1200 to a static IP of 10.0.0.12/255.255.255.0.The E1200's primary wireless connection works fine.  The guest access connects, but it does not prompt for a password and web pages generate a "failed to load" sort of message.I temporarily connected the E1200 as the main router and re-enabled DHCP, though I kept the static IP of 10.0.0.12/255.255.255.0, and in this configuration the guest access worked.  I observed that it connected via 192.168.33.1/guestaccess.cgi (or something very similar to that).