We had the exact same problem of losing messages/charts when the wireless network connection was occasionally lost. Nothing to do with the software or power, simply the operating system thought the signal was weak and lost the connection. Part was operator error in response to this situation though as you should never actually lose the chart.
To address, simply re-connect to a hard wired ethernet connection. This will allow you to save the chart even after the wireless connection was lost. Even if you make the mistake of exiting amazing charts after losing the connection, you should find that AC asks you if you want to "resurrect the chart". if you disregard that message, you will really lose the updates.
If your building is the problem and you have a weak wireless signal, you may need to either (1) install a wireless signal repeater or (2) install a hard wired network to serve as backup.
We ended up installing hard wiring into each exam room as backup. My theory was either our particular laptop/OS occasionally loses its connection or the building itself had too much interference. Rather than spending the time to investigate, it was easiest to just install a network switch and patch cables as we already had the rooms wired.
