Problem with fullscreen HD playback on 2.5.7

[Metti]

Hi
I have used BS-player for long time and i like the functionality of this media player. it simply has everything i need. It worked perfect until yesterday when i upgraded it to version 2.5.7.
the problem is that when i play any HD video and double click to full screen after some seconds the film hangs like it goes from and back with 2 frames, it works perfect when i put it back to the window view.
I downgraded BS- player to an old version and it works fine. the only problem with the old version is the subtitle downloader doesnt find any subtitl.
Does anyone know about this problem? i would really like to use the new version if it works. any help appreciated