Nether Portal not calculating coordinates

Sometimes when going through a Nether portal the game doesn't calculate the coordinates. 

Example: My Nether coordinates are 160, ?, 320. When going to the Overworld my coordinates should be 1280, ?, 2560. But instead the game skip the conversion and my Overworld coordinates are 160, ?, 320.

This has happened multiple times and sometimes causes death. Sometimes a portal isn't even generated.