Raspberry PI 2 and TPUART interface

[Giraz]

Hi to all,
I have a strange problem and I'm going to explane clearly:
until some days ago I was using a Raspberry Pi with a Busware Rot interface (TPUART) and all worked flawless with smarthome.pi last image.
Now I have a new Raspberry Pi 2 with the new Busware Pigator TPUART interface. I upgrade the smarhome.pi image using the old Raspberry, putted into the new Raspberry Pi 2 and all work well too, except for one dettail:

In ETS 4.2.0, when I use the function "download partial" i get this error:

Opening connection interface failed.
No connection available.

Any other function in ETS works correctly, the only limitation is that I have to use the "Download all" function each time I need to update a device, so I have to put the device into programming mode an then rewrite the physical address and the application. Group Monitoring also works well.

Investigating on the problem I try to put the new Pigator TPUART interface into the old Raspberry (the old Rot interface does not fit into the new GPIO connector of Raspberry Pi 2) and the download partial command works well. So the problem should be related to something about the Raspberry hardware, because the knx interface is the same and the eibd software and configuration is identical.

The parameters of eibd are exactely the same in both setup, this is the reply of ps aux | grep eibd:

admin     1736  0.0  0.1   3988  1848 ?        Ss   21:49   0:00 /usr/bin/eibd --daemon --Server --Tunnelling --Discovery --GroupCache --listen-tcp --pid-file=/var/run/eibd.pid --eibaddr=0.1.250 tpuarts:/dev/ttyAMA0

I can't find out which is the problem..

Anyone have some ideas?

Thank you in advance, bye!