Internet Explorer 6 Problem

I have been having a weird problem with IE6 ever since the install of winXP...very frequently while I am on the internet, I get a box that pops up asking if I want to stay online or go offline (the offline page viewing box)...this box is VERY annyoing. How can I get it to go away? Is there a default option to always browse online somewhere?

Thanks for your help,
Rob