Help w/ RG (ATT Uverse) and DD-WRT Router (I challenge the TechHeads)

My setup:
RG in computer room <Wireless>Linksys LINKSYS|WRT54G2 (DD-WRT Firmware) in Living Room <Hard Wired> 360, Slingbox, PC

The Linksys connects to the RG WIRELESSLY and acts as an access point. 360, Slingbox, PC - all connected w/ ethernet cord to Linksys.

360 and Sling have Static IP's (.77 & .79) and PC is automatically getting an IP.

My RG occasionally locks up (TV cable box freeze, internet dies) especially when I'm gaming on my 360. I opened up my RG's webpage and when I look at the "Home Network" > "Local Devices", it only shows the Linksys device w/ a wireless symbol. After a few minutes, the IP address will change, but the MAC address remains the Linksys router. What I mean by this is that the 360's static IP will show up in "Device Details", after a few minutes, the PC's IP will show up, then sling, etc. in any order. But this entire time, Mac address remains the same (Linksys Mac address)

Summary.....
My RG sees the router as one device but three devices are connected to it. Although all three devices will work simultaneously,after about 10 minutes, the RG will lock up. After I turn off the Xbox, the RG will reconnect and back to regular service.