cdc_ether uses currently the wrong bInterfaceNumber(s).
It uses CDC Union information for bMasterInterface and bSlaveInterface 
which seems to be wrong. At least there isn't any relation.
I don't know what would be the correct way but with my patch the driver 
supports the mobile phone again and there should be no malfunction with 
already supported hardware.
For a bug report see
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/796006