Ah, those Ealing comedies, or at least the best of them– “Kind Hearts and Coronets,” “The Lavender Hill Mob,” “The Ladykillers”! They don’t make them like that anymore, even when they remake them (as witness the Coens’ misguided version of “The Ladykillers”). But still filmmakers try, the latest British attempt being this darkly comic tale of a homicidal eccentric who becomes the very protective housekeeper to a rural English vicar and his family (with a good reason for her extreme devotion tossed in at the close).

But alas, it’s another failed attempt to recapture past glory days. “Keeping Mum” boasts an able cast and some amusing lines. And the English countryside, in Gavin Finney’s lush widescreen cinematography, looks absolutely lovely. But the picture never really takes off. It’s generally too reserved. The comedy is at best grey rather than pitch-black. Too many of the humorous moments are pale, almost half-hearted. And when it does go for broke, it generally stumbles. The result isn’t terrible, but it is disappointing.

The set-up centers on Father Walter Goodfellow (Rowan Atkinson), Anglican pastor in the tiny village of Little Wallop. A gentle, befuddled fellow continually browbeaten by Mrs. Parker (Liz Smith), chair of the flower arrangement committee, he has a promiscuous teen daughter Holly (Tamsin Egerton), a much-bullied young son Peter (Toby Parkes) and a long-suffering wife Gloria (Kristen Scott Thomas) who’s so dissatisfied that she’s having an affair–so far unconsummated–with her brash, lascivious American tennis coach Lance (Patrick Swayze).

Enter Grace Hawkins (Maggie Smith), the kindly old lady who comes to take over the housekeeping duties. No sooner has she arrived, with a big trunk that looks suspiciously like the one a young wife had hidden her unfaithful husband’s dismembered body in years before (as we’re shown in a period prologue)–along with that of his mistress–than a dog that’s been perpetually disturbing the neighborhood with its barking disappears, the nasty boys who’ve been bullying Peter get their comeuppance, and Holly shows signs of responsibility. More complicated is her solution to the strains in the Goodfellow marriage, which involve encouraging Walter to develop a sense of humor and a greater interest in romance while insuring that the lecherous Lance–who has his eye on Holly as well as Gloria–shoves, or is shoved, off.

The combination of comedy and mayhem on which the script by Richard Russo and Niall Johnson is based clearly goes back to “Kind Hearts” and “Ladykillers” (and, given the perpetrator, to “Arsenic and Old Lace,” too). But it doesn’t quite take. The humor is very tame–as in Walter’s big last-act address to a clerical conference (Atkinson, in fact, is never allowed to let loose)–and though Smith is given a handful of sharp lines of dialogue, even she is mostly forced to coast. On the other hand, the comic violence never finds just the right tone; for the most part it comes across more as mean-spirited than ghoulishly funny.

But the major miscalculation involves Thomas and Swayze. While the others around them are underplaying, they’re asked to come on so strong that it’s almost as though they’re in a different movie. That mightn’t be a problem if either of them earned much audience sympathy; but they don’t. She’s shrill and overwrought, rather than likable, and he’s simply distasteful, not funny. (It might have been better to make the character British, played by someone like Hugh Grant.) They not only create an imbalance in the picture, but break its general mood whenever they become the focus of the action. But one has to blame Johnson for most of the problems; his direction opts for a sort of discreet adequacy rather than taking any chances, and the result is a little deadening all around.

There are enjoyable nuggets throughout “Mum,” but they’re sporadic, and in the end the movie is no keeper.