Problems while surfing the web.

Hi:

I'm having a very weird problem with my network. While
I'm surfing in the net sometimes (not always) I get
the "Action cancelled" or "The page cannot be displayed"
pages.

The problem is not a big one becuase I just have to
reload the page and everything goes back to normal and it
doesn't happens each and every time, just sometimes and
it happens more when I try to visit a new domain.

Does anyone has a clue of why this is happening?

By the way, it happens in all browsers. I have installed
IE, Netscape, Opera and Mozilla Firebird and is the same
in each one of them.

Please help me

TIA

Antonio R.

PS I'm not having any other problem with my network at
this time.