seed random number generator (RNG) in omnet++/veins

I'm trying to reproduce simulation runs in omnet++/veins. for this i've set the sumo seed in sumo.cfg which is included in sumo.launchd.xml :

<random_number>
    <seed value="0"/>
</random_number>

And I've also tried to set the seed to 0 in omnetpp.ini :

rng-class= "cMersenneTwister"
num-rngs = 1
seed-0-mt = 0

However when i run twice the simulation with this configuration, I've got different results. I am quite confident for the seeding of SUMO as when I set the penetration rate to 0 the results are the same (no communication).

What did I miss?

Thank you for the help.