Thank You hefty1!
After some testing it seems that I have Back Focud issues. I will try the trick and let you know. One thing still discourages me: is the problem a lens/camera combination issue or is the sensor "out of focus"?

I mean, if i adjust the focus to have a sharp DA* 16-50, am I going to experience Front Focus with other lenses?

Thank you in advance...

Hello.
I have just ordered the 16-50 2,8 lens. I didn't know about QC issues and FF/BF. I am really concerned about firmware fix because I've noticed that this problems occur widespreadely. So before i put my hands over my new lens I'm afraid I will have those issues too and I'm posting some questions for those who will feel about helping me with some informations.

Where can I find the firmware hack?
Do I need to go back to firmware 1.1?
Is it possible to revert to 1.3 after applying the modifications?
Does the modifications to the sensor alignment put out of focus the other -non DA*- lenses?

Thank you in advance!