hi!
the problem occurs when I right click on the USB 2.0 icon and choose scan
the avast! quick scanner window appear and freeze for a few minutes ;D
it says Initializing engine, please wait… and it take a long time to respond !!!
this should be repair as soon as possible 
I’ve seen this with faulty USB drive only.
I think you’re asking twice the same… haven’t you did this question in another thread?
of course not!
I’ve test on about 5 usb sticks and i got the same problem!
every time I scan usb driver, i have to open avast and choose scan removable media :