Here’s a tip for the perfectionists.
We need to get on the same page (that was not intended as a pun)…below the grid origin is shown.

Notice that it corresponds to a position of (0,0) according to the horizontal and vertical rulers.

We like it being (0,0). It’s the default. It’s natural. It feels good.
Sometimes, the origin changes to some other weird value. The most common cause in my experience has been due to interactively resizing the page as shown in this screencast. If you try it you’ll end up with something like this:

Notice that the grid origin is at (-3,1.5)
Go to the View tab, and click on the little arrow in the bottom of the Show group.

The Ruler & Grid dialog box has settings for Grid origin that you can use to fix the problem. Set the values for both Ruler zero and Grid Origin.

In Visio 2007, you access the Ruler & Grid Dialog box via the Tools menu

And of course, you can fix it directly in the ShapeSheet. Right-click off the page, select Show ShapeSheet

Note that you’ll be two pairs of coordinates (XRulerOrigin,YRulerOrigin) and (XGridOrigin, YGridOrigin). This matches what we did in the Ruler & Grid dialog box.
