I have the new 27" iMac and love it. I started noticing when moving the mouse the cursor jumps across the screen. I have a 2nd monitor connected via mini display port to DVI adapter. It seems to be fine if the adapter and 2nd monitor are disconnect. I found several posts on the net with reference to a similar problem only with the Macbook pro and a 2nd monitor. Has anybody else found this problem with the new iMac? I'm half tempted to run with the single monitor since it is so big but it just bugs me when something doesn't work like it should.