Thank you all for kind posts
Today I brought my PCX back home from dealers service center. They tried to find the source of the rattle i mentioned here:
http://hondapcx.org/viewtopic.php?f=2&t=747&start=20 ,but without success. So I decided to stick with my trusty saying: "If you want something to get properly done, do it yourself". I taped a microphone in the cavity near radiator and went on a short ride. Then I parked at my garage and listened to the recordings. I grabbed a wooden stick and systematicaly tapped every part near the spot from where I heard the rattle. I also laid under the bike and looked under the... i believe it is called fairings

. I found two possible sources of the rattle.
I believe this is the source of the rattle. (sorry for my poor technical english

) It is the axle that holds center stand. On the axle there is a pin and washer. Both pin and washer are absolutely loose. The washer already shows a lot of wear caused by rubbing with the pin. So I believe this may be the source of the rattle. However it is hardly believable that it can produce such strong noise. But when I tap on the washer it makes a noise similar to the rattle I have been hearing. So I keep on hoping that I have found the source. I haven't got time to test ride it after this discovery, but tomorrow I'm planning to buy 2 pcs of flat rubber gaskets and insert them around the washer to lock it into place and dampen any possible vibrations.
I have also found this:
I'ts a plastic zip tie with ... well ... snap-on thingy which popped out of it's place. It is unlikely that this can cause that rattle noise, but who knows. I will try to fix it also, but I will need someone with tiny hands
And since I'm happy you liked my photos so far, here is a teaser from todays test ride:
I promise I will get a better photo next time, without the power line

We have a lot of castles in my country. There are maybe 5 or 6 castles like this in 50km radius from my home.