BleepingComputer.com: Help, I can't get to certain sites

Hello,

I have been having a problem the last month or so connecting to certain sites that in the past, I had no problem getting to. Sites such as www.cnet.com, www.walgreens.com, www.midamericanengergy.com and others.

I have windows vista, and I use firefox as my browser, but the browser does not seem to matter as IE will not take me to those sites either.

I have run Spybot S&D, ran a scan w/ Avast Anti-Virus Software and have been using a program called spyware terminator as well as checked out my hosts log. All have proved useless in solving my problem.

I have read numerous posts w/ similar problems, but I have not been able to solve my problem yet.

Any ideas??

thanks in advance.