I was using a Presonus Firestudio 2626 with a digigmax fs.  I recently came across a Soundcraft spirit 8 24 console, and decided to get the motu 24i to handle the 24 channels from the soundcraft.  This weekend I was recording vocals for my group's new cd and I had a problem with the motu 24i dropping the sample rate.  It would just drop from 48 to 44.1 without any warning.  Sometimes, it would change during the middle of the guys singing, and of course the pitch of the song would drop and slow down lol!  It was interesting to say the least. 
 
Has anyone had any experience with this happening?  The tracks for music were recorded in 24/48 and exported as a stereo file from PT at 24/48.  I imported them at that rate and it would drop the rate about every hour.  I tried changing the settings in Sonar, but it was to no avail.  I still had to close Sonar X1, and open the PCI424 settings to reset it to 48000.
 
Any help would be appreciated!  Also, I know that some believe I should just record in 24/44.1, but The studio in Nashville I am working with wants the files as 24/48 for mixing.  Not to mention the tracks were recorded at 24/48.
 
Thanks!
Low

Make sure that the MOTU audio devices are disabled in windows.

Under Windows 7 and 8:
- right click the little speaker in the notifications area on the right hand side of the task bar
- select "Playback devices" then right click any MOTU device that shows up in the list and select "disable".
- Then do the same on the "Recording tab".
- then click "Ok"

In addition, You can also disable device sharing in Sonar as well.

Gotcha!  Thanks for the quick reply!  I will try that when I get back there. 

One last thing to check (I forgot it the first time), is make sure that the PCI424's clock is set to internal in the MOTU Audio Console. Then set the clock sources in sonar to one of inputs and outputs of the 24i.

I,too, use a 24io. I had this problem a while back and it ended up I had to update the drivers for the PCI424. Never had the problem since. Now that I said that it will probably start doing it again. LOL

I'm still waiting on the Windows 8 drivers. :)
I've been in touch with their tech support over a few issues with Windows 8, but luckily there are workarounds for them so I can continue working with Windows 8.
I have lower latency settings for my old machine under Win8, but if you're look to upgrade to Win8, I suggest you hold off until the new MOTU drivers are released.

Disable windows sounds to ( no sounds ) in control panel multimedia sound options .... Anytime windows command or incorrect mouse clicks makes a sound ,, it defaults back to 44.1 .... This was happening to me for a long time before i figured it out .....

Now that I think back, it did seem to do it every time there was an incorrect mouse click.  But, there were also times where it did it during the middle of recording without me clicking anything.  That's where the pitch changing and tempo slowing came in. LOL
 
Thanks for all of yalls help!