This has been really interesting and informative, thank you! Like I said, I'm a nitrox newbie and only the divemaster in Tahiti bothered going over everything in detail with me as a quick refresher. I didn't have my nitrox book with me, but I did have my tables and was looking at them while working with my computer.
My dive log shows that the first dive went to 107 feet for 44 minutes. The second dive went down to 93 feet where I saw those readings, and I know I ascended at least 20 feet after seeing the anomalous readings until I got a reading of 1.4. The total dive time was 54 minutes and the last half was coming up a reef so we had an extended safety stop drifting along.
It looks like my computer must have gone into the default mode. After the second dive, the computer read "FO2 50 and PO2 1.90." On the first dive, it read as "FO2 21 and PO2 0.89."
The surface interval was 1 hour, 10 minutes, so it looks like my computer reset into the safety default setting. Now I know to reenter the percentage at each dive.