Hey guys
I have used an Aladin ZO2 for around 4 years (the computer battery was changed a couple of months ago after 600 dives); and a pair of Inon 220s for the last 8 months. I can't say as I have noticed any problems. If the computer/transmitter lose sync this has always re-established itself with a few seconds.
On a couple of occasions I have found, after the dive, that no remaining tank contents data has been recorded - but I have never been able to estabish why.
Just as a matter of interest, I have found the tec support for the Aladins provided by Scubapro - and before them, Uwatec - in the UK to be excellent.