Which products are affected?
Google Earth 5.0

What steps will reproduce the problem?
1. Open the attached KML file in GE
2. Zoom in so that all the five boxes are visible
3. Zoom out slowly

What is the expected output or behavior? What do you see instead?
The boxes should disappear all at the same time. That is not the case: the 
narrow/high box disappears first and the wide/low box last.

What application versions (if any) are you using?
Google Earth 5.0
KML 2.2

Please provide any additional information (code snippets/links) below.
According to the KML specification, the turnover point for the visibility 
of a region is determined by the square root of the number of pixels the 
region covers as displayed in Google Earth. The test KML file is created 
so that the turnover point is the same for all boxes. However, it appears 
that it is the *width in pixels* of the box that determines the turnover 
point.

Region-test.kml 4.7 KB   Download