Workaround for Multiple Messages via OSC / Arduinome

Hey there,
I'm currently working on a step sequencer running on m4l/arduinome 64 and always wanted to switch over to OSC instead of good ol' Midi. But i can't find a decent workaround for the following problem:
I receive the udp Data, unpack it, dump the prefix for arduinome serial, extract row and column numbers and want to insert it into an matrixctrl. But I dont want my arduinome to work as an on/off switch (how silly that would be ...) but as a bunch of toggle switches so I'm trying to get rid off the multiple messages that arrive by pressing the key and again by leaving the key.
This is what I got so far :

(I integrated column and row data into one integer in order to process it with the if object wich can't handle lists (-___-) But after unpacking the numbers again by hand I magically get two messages again but I want to get only one ! . Any ideas how to do that ? (Under Midi I did it exactly as in this example but I didn't have to workaround the if object because note value is only one number and not two like in this case)

Thanks a lot for your help
Kindly regards
sparsepix