I'm seeing the same thing here, also with 3.8.1. I'm trying with a USB flash drive, plugged into an older Compaq P3 Deskpro. Told it to use 25Meg of ~64. It appears (from a "ps -eaf" output) that there is a "umount /mnt/uba1" that has been sitting there for (now) 30 minutes. All the while, the access LED on the USB flash drive has been flashing.