Focusrite Saffire Pro User Mix control 3.4 does not start audio engine by default

At the risk of teaching you to suck eggs, I presume you have a saved profile on your Saffire, I only ask because I run a Saffire 26 i/o (original) and occasionally I have to reload the profile, i.e. bit depth, sample rate etc. as it forgets.  I have heard that by running Sonar you effectively force the Saffire to set such things.
 
Just an idea Alex

Deleted this post as it's irrelevant now.

Ha looks like we posted at the same time!
 
OK I've located the root of the issue and fed some disinformation earlier (I swear I had the engine on before, clearly I was wrong).
It's down to the audio engine not starting straight away.
I'd be still interested to know if anybody can repro...
 
Please ignore anything I wrote above.
From the beginning...
 
STEPS
New project
Insert soft synth track such as rapture and assign a patch. Then assign MIDI channel.
Make sure you can play the instrument with a MIDI keyboard and hear it.
Save project
Close Sonar application (it must not be running).
Open Sonar with Saved Project
Select Track.
Play MIDI keyboard
 
EXPECTED
 
Sound comes out when Playing. Audio engine is enabled.
 
ACTUAL
 
Sound does not come out when Playing, this is because the audio engine is disabled.
 
WORKAROUND
 
Either press Play (which turns on the audio engine) OR click on the audio engine icon.
 
Why doesn't it turn on the audio engine by default?
 
(The Saffire Pro 40 is Firewire).
 
[Edited for trivial revision of steps]

Good point, I tried with a blank project (no template)... #6 still reproducible with Focusrite Saffire Pro 40 and Mix Control 3.4 - Thanks for feedback!

Hi Alex,
 
Question.... Does it do the same thing if the initial track inserted is not a midi or an instrument track? thx

I use a Saffire Pro 40 (driver version 4.1.4.18046, dated 1/16/2014) and Mix Control 3.41b. I have not seen this behavior.
 
I doubt it has anything to do with the Mix Control application, which does not come into play until you explicitly invoke it. I suspect it could even be uninstalled and the audio interface would still function, just without the convenience of a software UI. It certainly has nothing to do with starting or stopping the audio engine.
 
The engine will shut off automatically if for some reason it can't fill the audio buffers for 250 milliseconds. For example, a background process that won't let go of the audio subsystem or an interrupt handler that won't allow Firewire interrupts to be serviced. That might be an angle to explore.

Hi Alex,
 
My specs related to OS, Sonar, interface, firmware, driver and Mix Control are identical to your signature except that I am on Windows 8.1, not 8.1.1. I tried to reproduce the issue following your steps and could not, it works as expected here. That might not be what you are hoping to hear, but maybe it indicates that the issue is related to a somewhat uncommon combination of factors. Hope you can get it sorted out soon.

Another thought though as David say this may or may not matter are you running the Firewire interface in legacy mode as recommended by Focusrite. 

CakeAlexS
Earlier versions recommended the legacy driver, but Focusrite do not recommend legacy mode with Saffire Mix Control 3.4. I am running a chipset as recommended by Focusrite.
 
Cheers..

OK I could not find that on the Focusrite page but will admit that I did not look that hard.