The 2006 remake of When a Stranger Calls tried its best to fix what didn't work well in the original, but failed to craft a better film. While it's an overall great film, 1974's slasher precursor Black Christmas' most memorable plot point is that the killer's calls are coming from inside the house. The popularity of that reveal no doubt played a role in the making of 1979's original When a Stranger Calls, which began the film with a very similar twist.
To be fair to When a Stranger Calls, Black Christmas didn't invent the idea of a killer calling from inside the home of his target. That dates back to old urban legends, as many common horror tropes do. But Black Christmas is certainly the first film to make use of the scenario to its fullest extent. When a Stranger Calls failed to improve on its predecessor in that department, as the 1979 movie has the "killer calling from inside the house" story play out within the first act, then become a sort of character study on the killer until he once again goes after the one that got away.
Many viewers who have issues with When a Stranger Calls often cite the fact that the film abandons the more interesting initial plot early on, the cat and mouse game between the killer inside the house and the babysitter he's tormenting. Thus, the 2006 remake tried to make that part the whole movie, and while an interesting attempt to fix things, it didn't succeed.
When a Stranger Calls' Remake Tried to Fix the Original, But Failed
Trying to make a whole film out of the part of When a Stranger Calls 1979 that everyone remembers wasn't necessarily a bad instinct, or an illogical move. The problem is that the remake's creative team didn't do much to try and compensate for the fact that they tried to stretch a 20-minute sequence into a 90-minute film. The movie still focuses almost entirely on one character getting targeted by the killer, and the two other characters that pop into the story don't really contribute anything other than being found dead later on. Both kills are off-screen, and thanks to the remake's PG-13 rating, it's almost entirely bloodless.
Even the children that are being babysat manage to survive the When a Stranger Calls remake, driving home just how agonizingly tame this version is when compared to the original. The remake stretches part of a plot to full-length without adding anything interesting to fill the added time, features no onscreen kills, has no real tension to speak of, and is highly unlikely to scare anyone who's advanced past junior high. The basic idea may have been good, but When a Stranger Calls 2006's execution went straight off the rails.