Issue with Access Point

I just moved into a new place and I live below my landlords. They have a cord that runs downstairs to me. They have a BEFSR41, which I can access via the cable. I set up my WRT54G as an Access Point following the WikiHow guide How to Convert Linksys WRT54G to Be an Access Point: 14 steps (I can't post the URL due to forum restrictions). I then test speedtest.net for the cable from the wall (50ms ping) as well as tested the laptop into WRT54G port #2 (and the internet coming in to port #1 from upstairs) with no problems again got a 50ms ping. However, when I connect to that same Access Point as a wireless connection however, it hits almost 500. Did I do something wrong? Do I need another adjustment?