Which router do you have?
For b/g I'm talking about the wireless protocol b or g, g is faster.
For WPA2 I'm talking about the security protocol. Some old routers only have WEP, that's weak security now. The newer ones had WPA with TKIP, the more recent ones have WPA2 with AES. If you have WPA/AES or WPA2/AES you want those.
A few other people have the same router I have, Belkin N+. They said they had it set for b/g/n with WPA or WPA2 (to allow both) and they had problems. They changed it to b/g/n with WPA2 only and they connect fine.
So, you might need to play with your settings.
Also, for testing, just make a short password for now to get it to connect, then change to a longer more secure password.