I got that too occasionally since i play on 1.7.2.5. Havent been playing 1.7.2.5 a lot though, but most of the time it happens near a city, and lucky as i am, i get beaten up by zombies nearly everytime it happens. And it always comes out of nothing, not like when you open and close your map. It happened across different servers too. But for me it usually goes away after a minute, sometimes more. Only had to terminate Arma once or twice after waiting > 5mins. Dunno if its possible, but at first i thought Arma has problems loading some textures from the harddisk? Maybe its related to the graphical Artifacts bug? Im too on the latest 96061 batch, and no launcher, commander or whatever here.