Personally, I'd send it back to Delta P now. It's probably to do with the upgrade, seems like the biggest variable. I wouldn't want to dive a unit which had problems the week before without knowing what it was caused it. And I don't know if anyone other than Delta P could sort that.
I managed to reset one by accident changing the battery, and lost some logged dives and time and date settings. But it did manage to find some dives from the time and date settings it went back to. A bit like a VR Time Machine (TM). Sorted once I reset the date.
Good to see you guys today. The big tins on the unit worked really well, so despite being 2 inches shorter from spine compression, I think I have sorted the unit
Yay!
Digs.