I was just about to make a post trying to figure out my dual-monitor issue with my C600, and here you are with a C610. This is a very helpful link I found.... http://www.linux-laptop.net/dell.html
Hope that helps with most of your problems. Just a thought.. You can connect to your router with that laptop, then your problem is most likely a DNS problem. Try editing '/etc/resolv.conf' and adding the line 'nameserver 220.127.116.11' above everything else. Also withOUT the ''s.
Hope this helps,