I'm having an issue where I'm working away in Sonar and POOF! the sample rate changes! I have to close and reopen the program.
 
It seems like something else on the computer is sending a message to my sound card (motu 2408) to change sample rate. All of a sudden, everything in my Sonar session starts playing slowly. (I work at 48 KHz normally) - I only notice it happening when I'm working in Sonar. 
 
Anyone have that happen?
Cheers
JG

Is MOTU set as the Windows default? If so make sure Windows is using the same sample rate. Windows sounds should also be disabled.

I would go a step further along the lines of what Steve mentioned, and suggest that don't set your MOTU as the default device for Windows audio. I leave my onboard sound enabled to be that default device so that Windows and generic multimedia apps keep their mitts off my MOTU. Also, try disabling Share Drivers with Other Programs in Preferences > Audio > Playback and Recording if you haven't already.

jonogrant
I'm having an issue where I'm working away in Sonar and POOF! the sample rate changes! I have to close and reopen the program.
 
It seems like something else on the computer is sending a message to my sound card (motu 2408) to change sample rate. All of a sudden, everything in my Sonar session starts playing slowly. (I work at 48 KHz normally) - I only notice it happening when I'm working in Sonar. 
 
Anyone have that happen?
Cheers
JG

I am having a similar(ish issue) and also with MOTU, SPLAT but on Win10

Thanks for the suggestions. Yes, I tested "Share drivers with other programs" off and on, no difference. I use the MOTU out in windows but I did switch it off to test. Still getting random sample rate changes. I've used the MOTU/Sonar/windows for over a decade, this is a new one.
 
I wonder if there's a way I can check somewhere right after it happens what could be trying to access the sound card. I wonder if there is an activity log file for the MOTU somewhere? * I told MOTU tech support about it as well, perhaps they will suggest something.
JG 

jonogrant
 I use the MOTU out in windows but I did switch it off to test. Still getting random sample rate changes. 

When you say you "switch it off" did you disable Windows sounds (method 2 in the link-recommended for this situation) or just mute it (method 1), or what?
http://www.isunshare.com/windows-8/turn-on-and-turn-off-sound-in-windows-8-8.1-computer.html
 
If you just recently began to have this problem suspect a new application, or a driver change via Windows automatic updates. You can see if a driver rollback is possible and try that. http://pcsupport.about.com/od/driverssupport/f/roll-back-drivers.htm
 
 

MOTU helped me to resolve the issue, in case it helps anyone else, I'll post it here:
 
** If you go to >control panel/sound/playback devices, you right click and select the properties of the sound card (MOTU in my case) under "advanced", you can choose the sample rate default for when the card is in "shared" mode.
 
I think that's got it but I'll post back if not.
Cheers
JG