Same problem here.
I work with my Dell Ultrabook XPS12 + Sonar 3 + Windows 8.1
From the moment I plug in my POD HD500, it randomly crashes after 1 to 20 minutes.
I've been playing with my USB powersave setup.
On my dekstop I have windows 7 and everything work perfect never had 1 crash.
Please fix this bug, I really want to be able to record from my ultrabook.
Is Line 6 working to fix this bug?