"Reset audio engine" screws up levels in Kontakt?

There is a Run/Stop Audio button that only toggles the audio engine. The Reset button sends MIDI reset commands as well as cycling the audio engine. Sending a MIDI reset will zero all controllers, which, in the case of MIDI volume may be setting it to the max value of 127 (I'd have to double-check that). If that's the case, and you've set a lower volume from the synth interface, it will be louder after the reset, and will stay that way unless you set a MIDI volume in the track to initialize it when playback starts.

EDIT: I could be wrong on that. The Reference Guide suggests that only All Notes Off (CC123) is sent on a reset. This has evolved somewhat over the years, but I thought it reset controllers as well. If not, it could also be that Kontakt itself responds to All Notes Off by resetting other parameters. I know that I have to filter that out from what my Roland controller sends, because some synths don't respond correctly to it, and I think the Kontakt Player I have to use with Alicia's Keys is one of them.

EDIT 2: If the response to All Notes Off is the problem, you can tell SONAR to send individual Note Off messages instead by specifying

PanicStrength=1

In the [Wincake] section of Cakewalk.ini. 

EDIT 3: I confirmed that Reset MIDI and Audio resets Kontakt player's output level to 0dB, which corresponds to MIDI Volume CC7 = 127 (though Kontakt is capable of going to +12dB, but that's another issue). Howver, setting SONAR to send individual note offs instead of All Notes Off did not change the behavior of Kontakt, so I have to think SONAR is resetting Controllers as well, though I haven't tried to capture that with a MIDI monitor.

There's probably already a thread somewhere that documents all of this, but I think the bottom line is that you're just going to have to avoid the MIDI reset button (as I do) and set MIDI volume where you want it with the track widget, so at least it gets set correctly when playback is started.