I'm on my second Wisdom 2 right now and have encountered the same issue with this one as the last. The problem is centered on the "Safe minutes". They seem to be completely out of whack. Just this last weekend, I did a dive that had a short drop to 60ft, but then back up to 30ft for approx. 30 min. After completing the 3 min safety stop in 20 ft of water, we slowly made our way back to the beach. While sitting in about 9 feet of water the alarm started going off and the computer displayed I had only 4 min of "safe" time left. How is that correct? The first Wisdom2 I had did the same thing. First time I noticed it, dropped down to only 25 feet and 10 min later it was telling me I only had 5 min of safe time. In both cases, the no-deco bars on the left edge seemed to be showing properly. In the latest case, only 2 green bars, well short of any issues (not to mention that back at 9 feet, I could stay forever if I had the air). So, am I missing something? Or is it time to send another one back??