Don't know if this has been suggested, but for me anytime I plug in a USB device like a flash drive while Defraggler is running, and they try to safely remove it, I get a message that it's in use by a program, which turns out to be that Defraggler is 'using' the drive and I can't safely remove it till I close Defraggler. This has happened on multiple OSes and computers...
Please fix so that we can remove USB devices while Defraggler is running!!!