I can't say i have ever experienced that, but i primarily use a network source for my music. It could have simply been the drive you where using that was causing the problem. Not every drive uses the same usb to sata bridge board so its not entirely out of the question that your drive was causing interference some how. DAC's are the same and in some cases even worse as there are multiple methods used to transfer data adding a software aspect as well. For example the Ayres DAC seem to use a method that can very easily be influenced negatively by other devices using the same USB bus, a BDA-2 doesn't have this issue.
Chris