Video size in Youtube player

Question

YouTube

The player does not open to the full size of the display in full screen mode.
It looks like this:


This is a 720p video at 1920x1200 monitor resolution, 1080p looks similar, sometimes even worse. The player in rare cases expands the video to full width, to full height - never. At the same time, the vk.com or vimeo.com player shows correctly.
In total, 2 monitors are connected, another 1280x1024 on the right, Ubuntu OS.
Am I the only one with this bug? How to treat?

The HTML5 version expands to the entire display, but it is terribly buggy, and the fact that it has been so long is sad.

Answer 1

It seems that the player stubbornly thinks that I have a resolution of 3200x1200, and does not see that there are two monitors.
Wrote to developers
Any other ideas?

Answer 2

I have the same problem. Ubuntu 12.10, two monitors at 1280x1024. Full screen shows if the video resolution is FullHD.