Jada, who clearly just saw the movie, is taking issue with several scenes, including one where Pac reads her a poem. She says, "I didn't know that poem existed until it was printed in his book."

She also says they never fought backstage at any of his shows ... as they do in the movie.

Jada and Tupac met in high school in the mid '80s. She's described him as one of her best friends, and although they kissed once ... she says it was never a romantic relationship. Jada was even the inspiration for some of his poems that were published after his death.

She does praise Demetrius Shipp and Kat Graham -- who play Pac and Jada -- for their performances ... but definitely shades the screenwriter.