Macbeth and the curse?

The story goes that Shakespeare overheard some Rumanian gypsies enacting a curse and put it verbatim in the first production of the play. The gypsies found out and 'cursed' the play. Things went from bad to worse and Shakespeare re-wrote the scene, alas too late. The curse has been with the play ever since. I saw Glenda Jackson and Christopher Plummer do it on Broadway. Miss Jackson broke her ankle and a flat came crashing down almost doing in Mr. Plummer. There is hardly an account of a production of 'the Scottish play' that does not contain stories of various catastrophes befalling the show.