OK, finally saw "The Uninvited."
Here are some of the similarities to DS I noted: the name "Windward" for the house, which sounds similar to "Windcliffe" Sanitarium, not to mention "Little Windward Island" on DS; a "malignant" (or was that "malevolent") house, which is similar to how Daphne describes Collinwood in 1840 (and, also, incidentally, seems to echo Nathaniel Hawthorne's "The House of the Seven Gables"); the sound of a sobbing woman late at night; flowers that wither suddenly; a woman in the past who falls to her death from a cliff near the house, and who now seems to haunt the mansion; the portrait of said woman; a floral scent accompanying a ghost's presence (cf. Josette's Jasmine, was it (one of my favorite teas, incidentally) and Daphne's lilacs) -- in this case, Mimosa (?), which I'd never heard of; an old book whose pages turn of themselves to reveal crucial information; and, last but not least, the perceived solution to a problem the family and friends are facing is to ... hold a seance!
I also noted that the male leading character's name was "Mr. Roderick," which seems to echo Edgar Allen Poe's Roderick Usher in "The Fall of the House of Usher." "The Uninvited" also seems influenced by Poe's story in having a brother and sister as inhabitants of the spooky mansion. Interesting how unlikely a scenario that would be today (a brother and sister living together).
Not all of these similarities with DS would necessarily jump out at you, and some of them are probably stock events in haunted house stories. Still, I'd agree with Luciaphil that the DS writers were inspired by "The Uninvited."
I enjoyed the movie, although not as much as I did "The Pit and The Pendulum," which I had watched the night before.
The ending of the movie seemed extremely rushed, and a significant element blatantly ripped off "Rebecca" (I'm hazarding a guess, anyway, that Daphne du Maurier's novel came out before the novel "The Uninvited" came out; at least the movie "Rebecca" preceeds the movie "The Uninvited" by about five years.)
And if I were to compare the movies "Rebecca" and "The Uninvited," I'd say I found "Rebecca" vastly superior. I've seen that movie three times, and my appreciation for it grows each time. Perhaps I'll need to do the same with "The Uninvited."
"The Uninvited" had quite a bit of unexpected humor, as well as actually dealing with the supernatural, and so the two movies are really doing two different things. But the "Mrs. Danvers" character in "The Uninvited" was not nearly as effective, I thought. The movie needed to explore this character more, and her relationship with her "best friend" who had foresworn ever having children (hints of a possible lesbian relationship lurk here, as in "Rebecca.") And Hitchcock's direction of "Rebecca" is flawless.
The piece "Stella by Starlight" was lovely (if you have parents who were young in the 1940s, they're no doubt familiar with it).
It would be great to find a pianist who could play this at a gathering of DS friends ...