Hi,
I tried the firmware, but haven't had any disconnection with it unfortunately, so no time value to share.
I had a disconnection just before I installed it though, and tried changing the buffer of my sound card as Tatoupulus said, but it didn't bring back connection with MD. The only thing that does still is to check/uncheck the midi input (aside from rebooting MD). So it really does not seem like an audio issue on my side.
I will check the power saving settings next time, but I doubt it will lead to any conclusion. Those are usually timed precisely, yet the disconnections I encouter seem to come rather randomly (it really can come 1min after booting, or 5, or 15, or 60... and when it happens multiple times in a row I don't think there is any periodicity...).
Guillaume