After installing this beta AirVideo starts to ignore aspect ratio written in mkv file header. i.e. 720x480 or 720x576 with AR 4:3 should look as if they were 720x540 (or 640x480, 768x576, doesn't matter), but they are played as is - shrinked or stretched.
Strange, but after reverting to 2.4.3 nothing has changed. Or maybe I was wrong and that behaviour was all the time, and I just didn't notice it before.