I have precisely the same problem but, happily, from my seated position the odometer is hidden from view. This is one of the Alfa ergonomic benefits. More interestingly however was another problem I had getting the satnav to work properly on my unit. It is a Kenwood DNX4210DAB and from the moment of installation there was a disfunction between gps and screen display. Kenwood's answer was aerial malfunction and because the microphone on the phone didn't work this seemed to be a reasonable direction in which to look. However, that turned out to be nonsense.
Kenwood's units come with Garmin satnav and what they had done in my case was send out a set with a software/firmware conflict with the mapping. The unit would work happily for ten minutes and then freeze leaving the car icon stationary somewhere back down the road. I was about to give the thing a good kicking when some thought processes kicked in and (i) I relocated the aerial, which made no difference at all - in fact the problem seemed more pronounced, and (ii) I discovered the Garmin-Kenwood website was "suddenly" offering a map update for the set. This update had not been available in June or July but appeared this August weekend as if by magic. So I spent some money backing a hunch and, via USB stick, downloaded and uploaded a big map update. These things work by overwriting within the navigation package and my guess was that if GPS references were thrown at a totally new and up to date map package it might just work. Well it did and the set is transformed. So lessons learnt:
1. Do not trust "out of the box" nice looking kit. It may have been on shelf for months with one set of firmware or software updates might be incompatible with something else.
2. Do not trust manufacturers agents "fob off" suggestions. They will always suggest the installation was incorrect!
3. When you have a new unit fitted make sure the installer properly updates the software, firmware, maps and all, at no cost if you can get away with it.
4. Sit low in the seat so that the flashing odometer (which is a Canbus issue) doesn't mess up your enjoyment.
5. Get some John Petrucci (I suggest Lost Without You) to play on your iPod as this perfectly matches the mood you can get into when things go depressingly pear shaped.