Accidentally I disconnected the rm04 module and realized that without it the LEDs work perfectly, no blink at all and a really smooth light. I have already tried putting a 10uF capacitor between source and ground, but still nothing.
Tel me, do you use the Arduino to supply out the RM04 unit? This unit take lot of power, maybe you should supply it with external power if it's the case.
Personally I use the base plate that come with it's own power source, 1 amp, to power the Arduino. So basically, I do the other way around.