USB tree device naming in Parallels Desktop is not constant
Parallels Desktop 8 for Mac Standard Edition
When you reconnect a USB device and connect it directly to the virtual machine, different device name with "#2" on the end (e.g. "My USB #2") appears under Devices menu for the same device plugged in different USB port.
This is expected behaviour. It happens when there is no serial number is Device Descriptor for particular device.