HI Guys!
Did contact Yamaha on the last "revision" and they confirmed that the upgrade was done. Strange they did not place the mark that time, but i have to trust them, right?

After making the confirmation by phone to Yamaha head-quarters they did place the mark on the chassis number.
So, there goes the chance to change the 5th gear!
Anyway i just found ill make about 2-3k miles per year which is nothing, so i will not feel any difference on the fuel consumption!!!
My bike is definitively the US 2003 model. The documents say 2004 but thats the year of registration, not the manufacture year.
Cheers,
TM