Maintain sharp corners w/ line tool?

Does anyone know if there’s a way to make sure Flash MX will maintain sharp corners on a box with ragged lines?

I’ve made a square border with ragged, solid, long, wavy lines and sharp corners. However, sometimes after I’ve edited other parts of the file and then re-published to check things out, the sharp corners have been mysteriously replaced with rounded corners. I have to go back to the border and play around with the settings, changing the line type, in order to get Flash to put back the sharp corners.

Any ideas how to stop Flash from automatically changing the corners?

Thanks.