Lost screenplay formatting solved / inches vs cm

Dear Keith / Scrivener Team:
Thanks for a terrific program. I had a minor heart attack this morning when I resumed work on a project in screenplay format, and discovered that all formatting (Scene Heading, Action &c.) was set to general text. There are several solutions posted on the forums, none of which worked for me - until I remembered I had recently changed the ruler / units (Format >Screenwriting>Script Settings) from inches to cm. Reverting to inches restored the formatting correctly, but it might be worth flagging up that changing the unit of measurement should not be done midway through a project.
George Tiffin