i used this code in my test project (taken from manual):

Code:
i = 1;
        me = ent_pvs ( i, 0 );
        while ( me )
        {
            if ( my.string1 )
            {
                draw_text ( my.string1, 350, i*12, COLOR_WHITE );
             }
            else
            {
                draw_text ( "-------", 350, i*12, COLOR_WHITE );
            }
            
            i++;
            me = ent_pvs ( i, 0 );
         }


Sometimes (almost, not all) this code draws one entitie more than in the count of pvs. All the entities in the level are opaques.

A toke a couple of screenshots:



In both cases there is one text line more than in the count of pvs. In the first example it looks that there are two "FNC_Jugador" (string attached to player entitie) and i'm totally sure that there is only one.

I have done tons of tests to confirm it and it looks like a bug.

Salud!