Flash build showing different behaviour inside iFrame

Our client has just implemented a game on their website, and asked us to check if everything worked properly. Because small parts of the game run outside of flash, for the sake of setting up communication with the web page, they chose to put the game into an iFrame. But for some reason, when the game is viewed inside the iFrame, some parts of the game scale down in width by one pixel. This creates a dark gray line (#262626) on the right side of the game with a width of one pixel in some parts of the game. The line is part of the flash file, because sometimes small parts are still drawn on top of the line. The smaller width also rescales the game, making everything a little bit blurry. This includes all text and images in the game, so it rescales the entire thing.

When I view the webpage that contains the game, so the page that’s shown inside the iFrame, in a separate tab, there’s no problem at all.

The webpage doesn’t seem to have any code that rescales the contents of the frame or the game, and the problem only occurs in some parts of the game.

Do you guys have any idea why this might be happening?

Ah! Just figured out what’s happening: the parent webpage uses percentages for position, and apparently it’s positioning in half pixels when you do that. The issue only presents when the screen has a width of an even amount of pixels, which in this layout apparently means that things are positioned by half pixels. So the game is in between pixels, and an in-game pixel differs from an actual pixel.

It might be worth to look into fixing this though…