Bad input lag in Windows Store build

I've found a distressing issue when trying to make a Windows Store build of my game.

When I test it in Chrome from Construct 2, play the HTML5 version from my website, or play the Node-Webkit build, everything works correctly. But when I deploy the game from Visual Studio and play it, my keyboard controls sometimes have some really bad input lag. Sometimes, I may be walking one direction, then I press the other direction to turn around and it takes an entire second to stop moving forward.

Has anyone else ever encountered input lag like this in Windows Store versions?

Youre probably in debug mode logging all the data frame by frame.

That's what I thought too, but switching it to release configuration, deploying it to my PC, and running it from the start menu doesn't help either.

Note that the framerate is fine - it's *only* the input that lags.