I made a test BD, and video didn't show up on the PS3, while in an old standalone BD player it worked, but after few seconds "slowed down" and remained as is, until I skip to the next chapter; then, it played OK but after few seconds slowed down again etc.

Yes, I used the Bitrate Viewer; I agree it is not perfect, but I tested it with a LOT of other .m2ts files from BD - even my own old project - and none had spikes over 40mbps, while the one I did following bd compliant settings had many well over 50mbps...

I tested further settings; as I need an average bitrate of about 23mbps to stay inside a BD-25, I tried to set -vbv-maxrate and -vbv-bufsize at the same value as the bitrate, and this seems to work; spikes are not under 23mbps, but often over 30/35mbps, still under 40, so I'm going to give it a try for the whole movie; after that, I'll burn another BD-25 and try it with both PS3 and BD player; if it will work, I'll try to test it further in some other standalone players.

This is until I'll install (again) from scratch the OS, this time using a "twin" PC of mine...