Hi. I happened upon this site from a google search where people were having similar problems to me - but none exact.
I hope you can help (and I hope I put this in the right forum).
Here's the deal - I have SBCYahoo DSL and recently moved to a house with only 2 phone jacks. so I decided to get a wireless network card for my desktop, to use with my existing (and working) Linksys BEFSX41 Router and Wireless access point. I should add that I have always been using a wireless laptop and a wired desktop - both of which worked great.
Since I installed the wireless card, and upgraded the firmware on both the router and access point, I can surf some sites but not others. For example, I can get to fourms (like this one) and google, but not cnn.com or hotmail.
After I did some research, I thought it was an MTU issue. So I figured out what it should be and I enabled it on the router. That didn't help.
If I connect using the sbc software, I have no issues at all - except of course the one of not being behind the firewall.