problem configuring wireless router as access point

here's my setup. i have a linksys WRT54G connected to my cable modem that acts as my main gateway. i also have a netgear WGR614 that i'm trying to configure as a wireless access point. i followed the setup instructions on the netgear site to the letter, but i still can't get my computer (TiVo, actually) to see the gateway and acquire an IP from it.

the instructions on the netgear site assume that the gateway router is wired, but there is a caveat that says to use different SSIDs if you're using two wireless routers in this setup. however, at another point in the instructions, it says to make sure all SSIDs are the same. right now, the SSID on the netgear AP is different from my wireless network. if i change it to be the same as the network SSID, will it work, or will the two routers just conflict with each other.

lastly, they also recommend using different channels on the two routers. but i read somewhere else that using the same channel on all wireless devices increases transfer speed. increasing network speed was my main motivation behind reconfiguring my network, so are there any drawbacks to using the same channel on all wireless devices? for the record, there are at least five other wireless networks within range of my house, but none of them are very strong.