We have a 4x with 5.2.9 (upgrading tonight to newer) and we just mounted a USB drive in the box. The memory page is seeing all the new memory (44 days worth) but it won't copy the existing user data and recordings over to the new drive. If I go back to internal storage the memory page shows a number of people with voicemail, but with the drive mounted they all show 0 seconds. We have pressed the CLEAR USB but still nothing.