This is an old issue that happens in every version of AP going back to 1.6. Whenever a new doc is created, as soon as I manipulate the art board using Trackpad gestures (pinch to zoom, scroll) , I get the graphical mess obscuring the blank view, effectively preventing me from even starting. The weird thing is that it manifests after long period of inactivity or - and this is just a wild guess – after system reboot. I can never know when and why it will emerge again. Launching it more than once, I now can't even get those zigzags to record with QuickTime Player to demonstrate. Occasionally, the mess occurs when I open a new doc but other than that it goes away. I know for sure the issue keeps out of sight to return later at some point.
The OS in question is Mac OS X Lion.