That should be fine, a home networking router can be used as a DNS server. It will just go out to your normal DNS server, look up what you need, and return that to your computer. If you still think this is a DNS issue, try going Start > Run > cmd. In the DOS prompt that comes up, type ipconfig /flushdns. This will flush your DNS cache of any pre-existing entries and obtain them all anew. Also, you can go into your router's control panel and look up the DNS server it is using. I personally put my DNS settings in my computer directly just for efficiency. If your router is causing problems with DNS lookups, this may be your problem.
And for the last damn time, have you tried eliminating the router? Just plug your computer straight into the modem? Before you come on Allakhazam and start spamming us again, why not listen to the suggestions that were made before? -_-