What FPS are you supposed to have? My FPS normally ranges from 30 to 40. However, when I hover my cursor over a gate or item you can click on it drops and ranges from 20 to 30. Can I fix those drops?

PST has a strange game loop, where the fps is tied in with the game logic updates.
So if you increase your fps you also increase the game speed

The original MAX fps was 30. GoG bumps that up to 40 fps (in the config file)

For some reason alot of the newer graphic cards run DirectDraw stuff really slowly.

to get a solid fps rate you could try this ->
http://www.shsforums.net/topic/48732-ddraw-fix-for-slowdownsstuttering/