How to reproduce the Issue:
1. Open a new graphics document.
2. Draw a square and fill it with black.
3. Type a text block and change the text color to white.
4. Select the text block with the arrow tool and change the pattern to clear.
5. Move the text block so that it is on top of the square.
6. Group the two objects.
7. Rotate the grouped object.
Objects with other text colors do not disappear. In other words, substitute step 3 with any color besides white and the text block will not disappear.
It should be noted that the white text will print to LaserWriters (PostScript) printers, even though it does not show on the screen. The white text will not print to QuickDraw printers such as the StyleWriter and DeskWriter.
The Work-around:
Substitute step 4 with any pattern other than clear. For example, if you want white text on a black background, use an opaque pattern and fill the text block with the color black.