Cannot load certain sites - returned to modem registration page

[James]

Hi,
Just about two weeks ago, January 10/11, I began having trouble loading
certain websites on my computer. Sites like www.welt.de or www.n24.de or
trebbs.com will return me to the comcast.net modem activation page (with the
text: "You will need to activate your account and create your Comcast.net
email address and password. To continue, please follow the installation
instructions.") I've had my account for nearly five years or so, so that's
not the problem. The modem was switched out and registered with Comcast.
And re-registered. The cable leading to my house was replaced. The only
other option that comcast gave was some kind of setting in Vista that could
cause the problem. Does anyone have any suggestions or information what
might be the problem? Could it be the 1-10-08 update to windows?

Thanks,

James

 

[James]

My parents have a DSL modem, and using that modem, I can connect to some
websites still, and have problems with others, as before.

James