When you can't connect to your home/work WiFi WAP

I had been tearing my hair out because my new HTC Legend couldn't see my home WiFi and yet occasionally it would "see" a weak signal from a neighbor's house.

My Access point was running WEP so I changed it to WPA-SPK - still no good.
So I also set up a second standalone WAP running WEP.
Still couldn't see either WAP.

Upgraded to latest ROM firmware. No difference.
Long story short, it wasn't the type of security, it was because I was using Channel 13

It suddenly occured to me that not all countries (I'm in Australia) have Channel 13 available so the phone might not have it either.

THAT WAS IT!! Changed WAP from 13 to Channel 6 (although any other but 13 would no doubt work) and everything worked.  

I have the same wifi issue on my PS3, PSP and wii. I don't know if it is my router, it will go as far as assigning an IP address to the device and the device can pick up the signal. But it will not further. For example, my PS3 could not get updates, even though it can pick up strong signal from my router. Anyway, enough history here is how I fix this problem on my Legend and all my wifi connected devices.
Manually type in 2 DNS address. (First, you have to find the DNS. Open command prompt in your computer and type in ipconfig /all) It usually shows 3 DNS addresses, pick 2 that is on different network (first and last one).
In the case of the Legend, you can't put in DNS manually without changing the IP address to static first. So you need to find an IP address that is not in use or you simply pick the one that is assigned to your phone already. If you pick an IP that is already in use by other device than both devices may have issue connecting so make sure to pick an IP that is free. Check DHCP client table in your router.
Now, I dont remember if my Legend ask for the mask, if yours ask for it punch in 255.255.255.0
I only have the phone for 2 days and so far I am enjoying it. Only minor issue is the battery life and it get hot during long use.

I hope this help.
lasermay2002