the pulsewidth is not linked up with the problem because the led on port D doesn't glow properly when it's just switched on.
i think you can easily imagine what connections i've made: power supply, crystal, port b and d connected to LEDs. it's a straightforward thing.
besides, PWM doesn't work this way. the shortest pulse width is too long for proper operation unfortunately so i can forget it all.
does anybody know another mthod to control the brightness (at least in two brightness-steps) of each of 16 LEDs without consuming too much space?