Proof for the Macbeth curse...?

I can cite one that I was in: the actor playing Banquo dropped a prop dagger and by freak accident it bounced and hit him in the arm. He required several stitches and we had to have somebody else read in for him the rest of the play. It's the worst accident in the history of my theater troupe.

I can give a few from personal experience. We were doing the show mighty man and the zombie curse (which is a real show, by the way) and it was opening night. One of the techs decided to be a jackass and yell Macbeth as loud as they can while walking under a ladder. That day Eulalie, who needed to jump around and run and all that jazz, twisted her ankle, as well as X12, who was wearing rollerblades. Also, during a production of Bye Bye Birdie, someone kept saying it during act I and, during intermission, a house just broke in half for no apparent reason.

during the first ever performace, hal berridge, the actor playing lady macbeth (women weren't allowed to act) died back stage.

in a production in amsterdam in 1672 the actor playing macbeth accidentally was given a real dagger and murdered the actor playing duncan live on stage

during 2 rival performances in 1849 a riot broke out leaving over 20 people dead

in john gielgud's 1942 production 3 actors died, 2 of the witches and duncan. then the set designer comitted suicide

david leary's 1972 production endured 2 fires and 7 robberies

in cambrige, 2001, macduff injured his back, lady m hit her head, ross broke his toe and two trees fell down and smashed the set to pieces