"I do not know why, but the page(at NetZero) says that is you are having trouble running other browsers, you should ask the browser
provider about it!"

That is reasonable Bill. ISPs get plagued with "How do I do this with this?" questions and "why is this going wrong questions?" Imagine trying to cover every possible combination and having people able to answer?

I still doubt (though I conceede the timing sounds good) that an ISP would make a change that could render customer's browsers usless. In general, that would go against business logic.