svcd resolutions 480x480 ?
 

I know that few of my files are either 480x480 or 480x576 but bsplayer shows that they are something like 768x480 or 640x480.
Any ideas, why ?

This is ok. It gets aspect ratio from file.
It should still show 480x480 but movie window will be 640x480.
You can check video info. It will probably be something like line below:

Video size 480x480, Aspect: 4:3 (640x480)