thanks to point me right directions...
i found out that extensions.cfg rows contains spaces (dont know where i took this code, but in this thread it is ok)
so instead of this
jpg: @JPEG_image: 2: pbimageviewer.app, picviewer.app: ICON_JPG
it has to be
jpg:@JPEG_image:2
bimageviewer.app,picviewer.app: ICON_JPG
then it works correctly, thanks again for patience