The original poster in the Steam forum has responded, and the problem seems to have been fixed by that advice.

More detailed instructions, for future readers:

1) Start Nvidia settings and add game.exe to the 3D settings tool. (This is needed because the Inspector tool only judges based on the executable's name, and "game.exe" is used by many games. Adding it from Nvidia settings generates a profile using the full path.)
2) Download the inspector. As of now, the link is here: http://www.guru3d.com/files-details/nvidia-profile-inspector-download.html
3) Start "nvidiaProfileInspector.exe".
4) From the "home" icon at the top, select the profile with the game's full path.
5) In the "Frame Rate Limiter" setting, select a value of about 60fps.
6) Click "Apply changes" at the top.

EDIT: I guess I can't mark my own post as the solution, or change the thread's title to say it's been solved. That's kind of a problem...

Hiya Gist,

I don't know if you still have this problem(it says solved but you've said it still happens), but what worked for me is using MSI / RivaTuner. Going through Nvidia didn't work for me so found a workaround through limiting my Max Frames through Rivatuner.

What a ridiculous cluster to have to go through so the game works like it should. Really weak QC job by the company. I just tolerated it with captions on and after a certain point in the game, it seemed to stop doing it.

The Nvidia Inspector solution is rather old, now that Nvidia has included frame limiting options in its control panel, and it will only work when the game is run on an Nvidia GPU.

From what I understand, the game does use VSync, but it seems that VSync doesn’t work well nowadays on pre-DX9 games. One solution (and the one I currently use) is to use a DX8-to-DX9 translator, such as this one. Just copy the DLL in the folder where Game.exe is located, nothing else to do, you will have VSync hence frame limiting. Of course if you’re using a high frequency mode (probably anything over 60 Hz) that may not be enough, but for the other cases it should be just fine. Additionally, converting to DX9 opens the game to a variety of tools and options that are not available to pre-DX9 software.

Thank you so much, that fixed it for me.

Just thought that I would add; this fixed it for me as well. Just google 'd3d8to9' and a GitHub page will pop up right at the top, download the file (it's a .dll) and you're good to go. I always find GitHub a little confusing so if you're getting lost like me; you can find the file at the 'Releases' tab on the right side column, below 'About'.

(I don't know if it was necessary, but I popped the .dll in the C:\Program Files (x86)\GOG Galaxy\Games\Syberia 2 folder... Why not)