I had the same problem with my pod x3 and i think I have a solution. My computer is a Dell inspiron 660, intel processor, windows 7 home premium 64bit, 4GB ram. I noticed that Intel Rapid Storage Technology application was messing with my cpu performance so i updated it and now my cpu usage stays low and my pod seems to be working great. After 3 long sessions in cubase with the pod as an audio interface ( i stayed offline with my antivirus disabled, just to be sure) , i had no audio dropouts neither loss of usb connection.
I guess it's too soon to make certain conclusions but if your computer uses Intel RST you can try updating it. If that's not the case you could try to find similar programs that affect your cpu usage and conflict with your podx3.