Never heard of this problem
by freetexas - 10/19/12 5:35 AM
I have a mid 2007 iMac running Snow Leopard. Within 10 min after booting up an area about 1/2"X1/2" appears to the lower right of the mouse pointer consisting of 8 columns of very small horizontal dash's that moves around with the mouse pointer. When this happens everything else quits working although the pointer still moves around in response to the mouse movement. I ran the tech tools from the Apple care disc an everything checks out fine.