No MAC address filtering is on, I verified that when I was checking the password in clear text. I also verified that the password was being typed in properly, with case sensitivity. I went so far as to type it out on my desktop, copy and pasted that to the router, then put it on a flash drive and copied the file to the laptop to copy and paste into the password field. That didn't work either, which is when I busted out the iPod Touch to make sure something in the same area could connect to the network (the Wii is on the other side of the room so I figured there could've been a difference in interference/signal strength/etc).

I try to avoid MAC filtering since we've seen in the past how easy it is to spoof that stuff.