Q: 9 square grid appeared

Browser or Viewer?

If you really meant the Viewer then make sure the crop tool isn't active.

Can you turn it off, if you uncheck it in the Crop brick in the Adjustment panel?

That does look a bit weird.

In the headsup for the crop tool (the blaclk window)  is the Show Guides checkbox. Try toggling it.

In the Adjustment pane is the checkbox to remove the crop tool from the image.

If that all fails try Aperture 3: Troubleshooting Basics Specifically the section on removing the Preference file. The description for that is about 2/3's of the way down the page.

Make sure you aren't showing the camera's focus points.  "View>>Show Focus Points" is the command, iirc.

(Using iPad, can't check.)

Ok I was right that is weird. That is not the crop tool grid, it looks like outine for selected images similar to this

In your image you can even see one of the boxed has a stronger outline, that would be the primary selection.

Try removing the preference file as I wrote above. UI issues are often times fixed by that.

Could be the focus points, never thought of that.

My 40d looks like

but I suppose other camera's points would look different.

Glad you got it fixed.

What camera by the way?