Having some issues with this game (using it via a couple of emulators, pcsx and xebra)

I am following the walkthrough (as per the pc version) on level 7 (last of the monastery levels) after pushing a lever/button on the top left most gargoyle by the coffin (right in front of your start place) it reveals an opening on the left most coffin in the room (to reveal an underground swimming area) after you press this buttion on the gargoyle you are supposed to go clockwise around the coffin that sits between the left and right gargoyle and after some time some small boulder is supposed to materialize which you must carry into the underground swimming area where you drop it and it sinks to the bottom hitting a switch which opens up the grating halfway down the underground swimming area, on the psx version, it doesn't matter how many times clockwise you go round the central coffin, this boulder doesn't materialise, the only way you can open the grating is by going into the swimming area yourself and hitting the switch yourself by swimming down to the bottom for it

(whereas on the pc version, as soon as you enter this level the small boulder reveals itself without you having to go round the coffin clockwise for some time)

On level 8 (the first of the mine levels) according to this walkthrough, there's supposed to be a medi-kit directly opposite the tracks from your start place, on the psx version it isn't there (on the pc version there is)

Also on level 8 going round the left end of the tunnel and coming out in the clearing, there's supposed to be a group of 3 crates, 1 on it's own and 2 diagonally opposite each other , in this walkthrough, there's supposed to be a swipe card at the back of the 2 crates on the pc version it does exist, on the psx version there isn't one there (and i have searched the whole area around there, including that whole clearing at the left end of the tunnel) and you need that card to power up the 2nd terminal

Is there a bug in the playstation/psx version or is this card elsewhere

Any help is greatly appreciated