Try doing a "ping cnn.com" from a command prompt. You won't be able to actually ping it, but it should return the IP address of cnn.com on the first line of results. If it doesn't, then you are having a dns problem. Try checking your dns settings on the router and on your PC.

That is really quite strange. cnn.com will never return the ping because they have their firewall set to not reply, but the fact that it returns the IP address implies that you have both DNS and connectivity to the Internet working. If they have software running on your machine that allows you to connect, that is something I haven't seen. What you might try, is with your machine connected directly, do an "ipconfig /all" command from the command prompt and see that the settings it returns are the same as what you have configured on your router. Also, from a command prompt, try doing a telnet "ipaddress returned from the ping command" 80 command and see if you get a connection. You won't get anything but a blank window if it succeeds, you'll get an error if it fails. It should look like this "telnet 192.168.0.10 80" remove the quotes and substitute the correct iP address. Is there any type of access restriction software running on that router? Like parental controls? Just a thought since you say you upgraded the firmware, maybe it's acting screwy.

Glad you got it fixed! Firmware updates? ...as the saying goes, "If it ain't broke....."