I just encountered the same problem. 67 happy dives with my SDA, and lots of air travel, both long and short distance. My last two dives were in the Mediterranean. The computer ended the dives just fine, entering surface mode, allowing me to log details about the dives, etc. After the return flight, the computer is now stuck at 2.5m of depth. I experimented with letting the battery run out and with vacuum bags, like lots of people on here. I found that the former compounds the problem: the computer locks up even more (when you finally get it to surface mode) because it has now logged incomplete dives and wants to clear the maverick diver of all possible issues. Eventually, I rigged up a vacuum cleaner with a small hose that fits snug into the pressure sensor opening (the round hole on the back with the metal cross inside). This allows me to surface the SDA (but doesn't let me bring it to all-green condition yet, as I can't let the vacuum cleaner run for 26+ hours). The hose has a slider on it that lets me open and close an air gap, thereby controlling the amount of vacuum the SDA is exposed to, and therefore the ambient pressure it thinks it's in.The vacuum cleaner gets the air pressure to about 800 hPa (down from slightly less than 1000 where I live). This lets the SDA exit dive mode. It stays in surface mode as long as the pressure doesn't exceed 831 hPa. When it gets to 832, the unit briefly displays "732" (!) and then enters dive mode at 1 m depth. This leads me to believe the following: the SDA doesn't enter dive mode based on some fixed pressure threshold. Instead, two things need to happen: First, a pressure change of 100 hPa (the difference between 832 and 732) has to occur, which is consistent with jumping to 1 m of depth in dive mode. When this happens, the unit takes the last value before the pressure change as the surface air pressure (in my case 732). This approach would allow for automatic consideration of different diving altitudes, as it doesn't use a fixed assumption of air pressure at sea level of 1013 hPa (roughly 1 bar). Second, this pressure change has to happen in a certain (short) amount of time, so that it doesn't get confused with a regular change in altitude while driving or flying. And that's where the problem is - for whatever reason, several flights did not cause an issue, but the last one did. Maybe the cabin pressure increased more quickly than normal, enough to trigger dive mode. Now, my SDA believes the correct surface pressure is a ridiculously low 732 hPa, and it wants to sit in that environment to finish its decompression. Even when I surface it artificially with my vacuum, it won't let me run a firmware update (to hopefully reset it all), because it's still decompressing. And I can't keep the vacuum running for that long ...I do believe the solution is to get the SDA to its imaginary surface pressure and to then gradually increase ambient pressure until back to normal. If this can be done at a slow enough rate, the computer should think it's just coming down from a high mountain, without triggering dive mode. I could try to go up a mountain to do that (as has been suggested), but my back-of-the-envelope calculation suggests that I would have to get above 2000 m from the 400 m where I live. And I'd have to stay there a while... (if I don't want to "change owner" and lose all my log entries, which don't exist online anymore thanks to Uemis' bankruptcy). Or maybe I should just take it on another flight?Any suggestions regarding how long the SDA might need to stay at it's imaginary surface pressure and how fast or slow the rate of approaching normal can be?Sorry for the long post, but I thought it might be helpful. And maybe I can get my questions answered too.Thanks!T.