Adobe Illustrator CS5 Working with drawing modes

I am a rookie.  I have CS5 and got the book with disk to learn Illustrator CS5.  But the disk is broken.  So am following lessons building as I go.  On page 18, Working with drawing modes. . .I run into problems at step 6-8.  I follow step 6 (and it's not easy to hold down shift key while rotating counter clockwise).  This is a step that will take away part of a rounded rectangle as I am learning to draw with shapes.  I set the drawing mode to normal per step 7.  And at step 8 (Select > deselect) I expect the shape I just rotated to disappear taking a portion of the rounded rectangle with it.  That is what appears to happen in the illustrations.  But it doesn't happen.  If someone is quite experienced with this feature, please help me understand why this is not working as expected.  What I end up with is a gray filled rectangle that has been deselected on top of the rounded rectangle (white) rather than taking away a portion of the white rectangle.  See Classroom in a Book Adobe Illustrator CS5.  Thank you.