Low frames at some stages

I'm having framerate problems at some stages that I hadn't before.
Stages like Bergheim, Sieversdorf, Barum and the most recent one Fernet Branca, specially at areas with more tree density.
I already turned off almost every graphics options and the problem is still here.

Anyone had this problem? Is there a way to fix it?

Thank you!

yes me too, i have this problem. lag with ngp 4.2......,,, ngp 4.1 work good

I have it since stages got their 1.01 version (a long time before NGP). 1.00 Version was ok