logo is changing when sized down

I notice that the bowls (enclosed empty areas of letterforms) become smaller much faster than the black areas when the whole thing is reduced in size, and in some parts of the reduced logo, empty areas close up completely as in the space between the A, i, and C. That suggests that a stroke might be applied. If a stroke is applied, is it needed? If not, set stroke to None.

If there is a stroke applied, there is a chance that the little part that sticks out of the C is because of extra unintended points forming a tiny corner on the path where scaling caused it to pass its miter Limit angle, an example is shown in the demo below. If that turns out to be the cause, you have three possible solutions:

• Zoom in and delete the stray points forming the unwanted corner. This is a good solution because it would clean up the path.
• If you don’t clean up the path, setting stroke to None. That would also help because then there would be no miter limit angle to worry about. 
• You could also leave the path as is but adjust the stroke miter Limit until the spike goes way. But that would only be a workaround because if the path was scaled again, the spike could reappear.

There is an option in the Transform Panel (and other places as well) to Scale Strokes and Effects.

Is that turned on?