Apple TV 2G (Airplay and Homesharing) can only stream from devices on the same wireless access point range??

Question

connection:
40 Mbps Fiber Broadband connection using:
Devices:
1. Main Modem/router (AP1): Huawei HG8245 (provided by ISP) - Wireless enabled.
2. Remote Access point (AP2): Linksys/Cisco E3200 Wireless gigabyte router flashed with DD-WRT v24-sp2 (06/14/11) mini (Cascaded -wired- LAN to LAN from main modem).
3. Wireless Repeater to cover a dead spot  (AP3): Linksys/Cisco E1000 wireless repeater.
4. Apple Tv (AT2G) with home sharing/airplay enabled.
5.( Ipad) with home sharing on itunes enabled.
6. Win7 (PC) using iTunes with Home sharing enabled.
all devices are updated to their latest firmware.
In order to cover a large 3 story house with Wifi. I had (AP1) is located on the first floor, while (AP2) is located in the basement floor directly wired by LAN to LAN with (AP1). (AP3) is located on the Ground floor away from the living room to repeat wireless network into the back yard. While (AT2G) is located in the living room on the ground floor right in the middle of both (AP1) + (AP2) while connected via Wifi.
Network SSID, security, passphrase and wireless settings of (AP2) are identical to (AP1) to create a single big LAN/WLAN roaming network where all devices connected to both wireless access points can find/share the others. As understood, it's refered to as bridging.
I have noticed that my iphone/ipad does not show the airplay button anywhere within the wireless network. it seems that the apple TV randomly choses to connect to the AP with stronger signal, or switch to the other in case of a reboot to one of them.
to elaborate further, if i was sitting in the living room (groundfloor), trying to airplay some you tube contents via Wifi to my Apple TV, i may not find the airplay button available all the time, i found out the reason is while i'm wirelessly connected to AP1, the Apple TV was connected to AP2 and both deviced cannot detect each others to enable my purpose. that goes the same for Home Sharing. only if my Ipad/PC and Apple Tv are on the same wireless AP. they would detect each others immediately.
although, the second AP (AP2) is suppose to extend my wireless network of the same subnet in which any device connected can be found.
After all sorts of trial and error tweaking my router/access point, I thought the problem would be due to the Linksys 3200 capability of bridging WLAN and lacks few protocols that enables my purpose. i have flashed the firmware to a DD-WRT, but again, problem was not solved.
I have not tried having my Apple Tv wired to either router/AP, but i assume it may work well if i do so. i still need to solve this wireless connection issue though.
Am i the only one with this problem, would there be something wrong with my setup? 
Your feedback is highly appreciated.

Answer 1

You may or may not already have your network set up correctly, it's just that I can't tell from what you have said.
I have a main router provided by my ISP, I have several other Airport Extremes and Airport expresses connected by Ethernet, all set up to bridge the network created by the main router.
Each maker has their own settings, but bridging should be reasonably obvious. In simple terms my main router distributes IP addresses to all devices, the Airports bridge that network by passing these addresses to the devices from the main router. A base station that isn't in bridging mode will distribute its own addresses to the devices connected to it.
I don't really follow your next point.
instruction for configuration vary from manufacturer to manufacturer, the best course of action here is to refer to the manual. If everything is set up properly the addresses of everything on your network will have identical sets of numbers for the first 3 of 4 groups of numbers that make up an address, the last set must always be different. I think the part you are referring to with your DD-WRT is the option to have Ethernet and wifi bridged or not.
Some routers may be easier to configure than others, but generally speaking they should all work with the Apple TV. 5Ghz is less likely to suffer interference but it is much more likely to be blocked by solid objects, it may or may not be an advantage.