Line thickness issue

Okay I’m having an issue when it comes to line thickness on movie clips, when a movieclip is flipped the line thickness vanishes due to Flash thinking I’m squishing the MovieClip. Is there any way I can make Flash not bother the line thickness when changing scale or some sort of alternative? Or is my only choice to kill line thickness altogether (I’d honestly prefer not to do this but if I have no other choice)

Example: The right is the undistorted MovieClip.