Good place to look. I think you have the right code because in post 9 you mentioned that the code was 10 digits and only numbers.
Your router comes with the capability to install security on the wireless network so that the casual passer-by can't hop onto your network. It has a varitey of methods available: WPA/WPA2, WPA2 only, WPA only, WEP and of course you can disable the security. All this is shown on p39 (p21 of the pdf).
WEP security (Wired Equivalent Privacy) is the easiest to use (and btw, the least secure - but that's better than nothing). It comes in two flavors, 64 and 128 bit. If using 64-bit and using HEX, the code would be 10 digits long and can only use the numbers 0-9 and the letters A, B, C, D, E, F.
So this is the code to enter into your wireless adapter to access your wireless network.
Looking at p 39, you probably have
WEP checked
HEX checked
Key Provisioning - static
Default key = 1
If you can't get things working, how about removing security for a test? This is done by selecting DISABLED on the security page. After doing that, you probably have to go back to the TV adapter page and seach for the network. No password is required when the security is disabled.