Through my work for a film festival I have been coming across many films with a size of 1888 x 1062 pixels. This can happen when exporting 1080p films out of Final Cut Pro. To prevent this use Compressor for exporting your videos. In the "Encoder" tab of the compressor settings turn off "Add clean aperture information".
In the german version of Compressor the tab is called "Codierer" and the aperture tick box "Bereinigte Blendeninformationen hinzufügen".
This is not a very pressing issue, because the film does not really have 1888 x 1062 pixel. The cropping happens through the use of a "flag" in the video file. So it has the full 1920 x 1080 pixels and the Quicktime player shows them all. But still, it may lead to inconsistencies with other software players or when further transcoding the video.