In Netscape, one can stop the blinking by clicking CMD-.
In IE4.0 under Windows it stops withthe <esc> key.
Neither works in IE4.5 on the Mac. There is a stop download option in this application, but it is grayed out.
Is there a solution? If not, it's Netscape for me forever. The blinking banner is an abomination, a huge distraction when one is trying to concentrate on text.