Sonar with Line 6 Interface Keeps Crashing

Hi;
 
I'm a Sonar X3 Studio user.  I use a Line 6 UX2 for an interface.  Twice in the past few days I think the drivers for the UX2 have gotten corrupted.  What happens is I launch a project and Sonar freezes up and doesn't open the project.  When I cancel the launch by re starting the PC I go back into Sonar and I get this message:
 
"There are no audio devices for the current driver model on your system.  Please go to Edit/Preferences/Audio/Playback and Recording to choose a different driver model"
 
I then go to that area and choose ASIO and get this message:
 
"The following tracks and buses are currently assigned to a silent hardware output.  The items listed below will be silent in your project until their outputs are reassigned to an appropriate hardware output"
 
The item listed is MASTER.
 
Also, in Preferences/Devices there are no input or output devices listed.  Before the crash the ASIO UX2 drivers were listed there.
At this point I cannot get playback of audio or MIDI through Sonar for any projects.  Even new ones!
 
I fixed the problem (for now) by deleting then reinstalling the Line 6 drivers. They then re appear in the Devices listing and then I go back into PB&R and choose ASIO and I'm back in business.
 
My question is-Why is this happening?  Re installing the Line 6 drivers takes considerable time away from creating and is very frustrating.  A few weeks back I posted a question here about keeping the interface connected to the computer when booting up/shutting down (as opposed to unplugging it before shut down) and quite a few people say they do that all of the time without a problem.
 
Also, is there a quicker way to resolve this without re installing the Line 6 driver? ie, is there a quicker way to reassign the Master track from a silent channel to the ASIO one?
 
Note, this doesn't happen every time I launch a project, but it's happened on two occasions in the past two or three days. 
 
Thanks!
 
Johnbee

Yes.  The UX2 is shared with Reason 7 and Samplitude Music Studio 2013, but I never run more than 1 DAW at a time.  Also the USB is plugged into the back of the PC so I assume it's direct and not a indirect (hub?)
 
JB

I had a UX1 that was fine for years but I got a Propellerhead Balance so it got relegated to the cupboard. For some reason I tried using it again (with everything up to date - I still use Pod Farm 2 so I regularly run my Monkey) and it was an awful experience.
It got put back into the cupboard (or bin) and I moved on.
Obviously this story doesn't help but it goes to show that the UX stuff can take a turn for the worse for no good reason.

Grum.