Addition of unwarranted ties
1) Select a chord, say a tri-tone, or one note in the chord.
2) Select an adjacent note to which a tie is intended and activate the choice by pressing the tie button.
3) Notice that MS3 has added the tie and extended it to a third note as well.
Unfortunately I can't provide a screenshot. I'm not sure how to get one outside of the range of a browser app on my PC. A workaround is to manually delete each tie that was erroneously created.