Visual Glitch on -some- computers

Hello everyone, im having trouble with something i have no idea why it happens:
Apparently only 3 out of 350ish active players got this problem
They see random visual glitches, like the one in the SS below, or sometimes the models dissapear (like, not the whole model but a part of it, and it's not because of occlusion culling)
Or even they say they start seeing a lot of triangles instead of the meshes.

I tried everything that came to my mind, but i cant solve that, and the thing is, i can't reproduce it either.

This is the Spec of one of the players that reported this error:

Win 7 ×64 bit 6gb ram I3 Intel hd graphics 3000 graphics card

Can i get some help here?

 

Seems to be a hardware problem or just "hacking" problem. Maybe some models are missing, etc...

In your image (not too clear) i see a black plain drew on purpose. Try to get a movie with this bug.

Maybe this happens every 3 out of 350 programs, but i doubt it.

 

yeah, it's super weird because that black plain doesn't even exist in the project.
ill ask them for a video, but the download link for this guys is the same for everyone else, and only them had this problem.