Some sites won't load on wired connection only

Having a very strange problem on a brand new desktop computer. When i use the wireless connection, everything is great. When i switch to a wired connection, some sites load fine but others won't at all. I have other desktops on the same wired connection and they have no problems whatsoever.
For example, i can get to Yahoo but not Yahoo Finance. I can get to Google, do a google search, but can't connect to the resulting sites. Can't get to ESPN, but Logmein works fine. Tried 2 different browsers (Chrome and IE) and same results.
I uninstalled all anti-virus software and disabled firewalls. Doesn't make any sense. I've never seen some sites connect and some won't, yet the wireless connection works for all sites.
I tried releasing and renewing the Ipconfig, and tried flushing the dns. I'm totally stumped and incredibly annoyed.

Any ideas?

Welcome to the Seven Forums.

My guess is that you have too many tunnel adapters - that can cause DNS problems.

Tunnel adapters are specific to a network adapter - hence your problem with only wired connections.

Automating "6to4" Adapter Removal in Windows - RyanVictory.com

Thank you for your response. There was only 1 6to4 adapter listed there. I uninstalled it. It didn't really help. I was able to get on yahoo finance right after that, but sites like ESPN and Twitter were still not loading. Then after a restart yahoo finance wouldnt load anymore. I checked back in those settings and there is no 6to4 adapter listed there. I'm back to square one again. Any other thought?

if you connect via PPPoE, see if the MTU info in this thread helps
Issue opening websites, Facebook, MSN, Microsoft - IE9,FF10,Chrome

Very strange turn of events. Connecting directly from the modem to the computer (bypassing the router) did not solve the problem. It stayed exactly the same. After that, since I was completely out of ideas I tried using a different router, and it worked. I have no explanation of why it works now, but I can now connect to all sites and everything is good. Very odd.

Just out of curiosity, when you connected directly to the router...
...did you reboot the computer?
...did you cycle the power to the router?
...did you use the same LAN cable?

If you did not do those things, I'm not suggesting that you try those things now for fear that things could break again. I'm just scratching my head over this one.

I'm not sure what makes a router W7 compatible... never had any problems.