I've found out that if one chooses widescreen mode (16:10), and then uses the machine gun scope in the game, the top half of the screen will be covered up for some reason. This bug doesn't occur in 4:3 mode. I've attached some screenshots. Is there a way to fix this?

Any update on this? It seems to only affect the 16:10 ratio mode.

I played Quake 4 on my previous PC, which was running on Vista Ultimate x64, and in 1680x1050, and I don't remember getting this issue. It was a non-GOG copy of the game, though. Since getting the game here on GOG I've not actually played it yet, and I'm now on a different PC using Windows 10.

I'm wondering whether this might be related to the OS or maybe it is specific to the GOG version?