I have this night vision problem also.
On night missions, my NV Goggles simply will not activate. I have tried changing the key binding but nightvision still wont work. On one occasion, I restarted the mission three times and suddenly night vision worked but when I died, the night vision vanished and would not return. Â Another time, I finished the night mission despite not being able to use nightvision and the "mission complete" screen was iluminated as if I was wearing NV goggles! Its crazy.
I am also experiencing frequent problems with textures and animations not loading, though I understand that problem is linked to Nvidia cards. Â
I am running ArmA v1.05 on Windows XP. My system is an Athlon XP3200 with 1gb of RAM and a Geforce 7800 GS 256mb AGP video card.