Sequence effects matrix case 8 results in a final position 46pixels off initial position

Steps to reproduce:
1. Compile the attached mxml file
2. Click button 1, wait for at least two seconds
3. Click button 8, wait for at least two seconds
4. Click button 1, wait for at least two seconds

Actual Results:

The final position is shifted to the right by about 40 pixels.

Expected Results:

The final position should be the same as the initial position.

Workaround (if any):