wow! it worked out of the box. wired up my 6x6 led matrix and max7219. started arduino board and got a diagonal line 
. but i´ve encountered another problem! it seems my leds are not being switched off correctly. they lightly dim even when i call max7219_all(0x00).
up to now, i´m using the LED-grid with 1k resistors for each coloumn.
datasheet says sthg like this:
DIG 0–DIG 7: Eight-Digit Drive Lines that sink current from the display common cathode. The MAX7219 pulls the digit outputs to V+ when turned off. The MAX7221's digit drivers are high-impedance when turned off.
what´s the reason for this kind of "leaking current" ??