Thank you for the post.
I am able to reproduce this on Windows 7 and Mac OS X 10.7.5. I forwarded a full report to Testing and Development for review.
The workaround appears to be to use the same drawing tool for both objects. For example, if I use the rectangle box tool to make a 1 point blue box and a 1 point red box, then I am able to overlap the two objects on all four edges. If I use the line tool to draw two boxes, a blue and a red, then I am able to overlap the two objects on all four edges.
The issue appears to only occur if the two objects were created with two different drawing tools such as a box drawn with the line tool and a box drawn with the rectangle box tool.
I don't think that matches what Mikhail describes. He is only creating ONE box and snapping it to GUIDES, not another box or group of lines. The Guides are just to show how the bottom and left edges are off by one.
You are absolutely correct.
After reading this again, I now see Mikhail is talking about this feature:
The issue I discovered when I thought I was testing may be related.
1. New Layout (blank)
2. View > Rulers
3. Create a vertical guide
a. Drag out from the vertical ruler. (repeat)
4. Create a horizontal guide
a. Drag down from the horizontal ruler. (repeat)
5. Draw a box (.25 pt) within the borders of the newly created Guide box.
6. Stretch the box to the size of the guides.
Result: The top and left edges snap and overlap the guide, but the right and bottom edges are one pixel off.
I forwarded a full report to Testing and Development for review.