Here's an odd one that I've not encountered before, hope someone can help.
 
Running Sonar X1 (32b) on Windows 7
 
Recently bought a Roland V-Studio 20. Today was setup day!!
 
Everything installed ok with just the usual little settings changes but...
 
Now when I play or record, as soon as I stop I hear the sound of a USB being plugged in, quickly followed by the sound of the USB unplugging (you know 'duh-di' 'di-duh')
 
I presume it's something to do with the V-Studio but can't figure it out.
 
Any ideas? Thanks in advance

I'd try a different USB cable first. 
Then see if it's a loose connection. 
Then try a different set of ports. 

just make sure you installed the drivers correctly.
heres a video I made on unpacking and installing (its a sticky in the vs 20 forum)
http://www.youtube.com/watch?v=kLwsBlCEYyo
 
always, I stress ALWAYS make sure you plug the vs 20 in to the same usb port all the time (the same one you plugged it in to when you installed the drivers.
 
for example, if you installed the drivers by plugging the unit in to the front right port,
then always plug in to the front right port.
 
plugging in to the front left port can cause adverse effects on the way the unit handles audio and signal, as well as connectivity.

There is a configuration called "MinimizeDriverStateChanges" in aud.ini that controls whether or not audio devices are reset in response to transport changes (play/stop). (Too long to post; check the manual or the help file.) Perhaps your V-studio is allergic to the setting in your file.