I don't know the answer but I have the same router and sometimes I have to enter one of the 4, I think it's 10 character keys, and sometimes I have to enter the password that was used to generate the keys. I'm not sure why.
On a side note, I've found that NetGear products generally work, but don't work as well as advertised.
If you are using WEP, generally it is better to enter the HEX code generated by the router, rather than the password. This often comes down to different ways that passwords are translated by different manufacturers.
Better to use WPA (not WPA2) anyway as it is more secure.
I would suggest that you try connecting with security disabled in the router -- and while you're in there make sure that Access by MCD ID is not enabled (it'll be under Wireless Settings).