Notebook will not boot with internet cable plugged in.

Hi,I recently received a new toshiba laptop, but have been having some difficulty. I have a high speed connection, when I boot the pc with the cable from the modem plugged in, the tcp/ip configurations appear on the screen as it boots, but then it just freezes before even loading windows. However, if I plug in the cable after windows is loaded, then it works fine. Does anyone have any ideas? I am at a complete loss.Thanks!Andre