thm_w's post gave me the idea to suggest trying the U3P100 on another system (different OS) if you have one available to you. If you're running Windows, you can get VirtualBox or VMware (a trial should do) and install a Linux VM.
In a command window in linux, run the `dmesg --follow` command to see kernel events. For example, when I plug in a USB sdcard reader I see:
1675485.134833] usb 4-1: new SuperSpeed Gen 1 USB device number 2 using xhci_hcd
[1675485.163444] usb 4-1: New USB device found, idVendor=8564, idProduct=4000, bcdDevice= 0.04
[1675485.163446] usb 4-1: New USB device strings: Mfr=3, Product=4, SerialNumber=2
[1675485.163447] usb 4-1: Product: Transcend
[1675485.163447] usb 4-1: Manufacturer: TS-RDF5A
[1675485.163448] usb 4-1: SerialNumber: 000000000004
[1675485.215596] usb-storage 4-1:1.0: USB Mass Storage device detected
[1675485.217098] scsi host33: usb-storage 4-1:1.0
[1675485.255421] usbcore: registered new interface driver usb-storage
[1675485.266281] usbcore: registered new interface driver uas
[1675486.290967] scsi 33:0:0:0: Direct-Access TS-RDF5A Transcend 0004 PQ: 0 ANSI: 6
[1675486.296491] sd 33:0:0:0: Attached scsi generic sg2 type 0
[1675486.618869] sd 33:0:0:0: [sdb] Spinning up disk...
Who knows, maybe the U3P100 will generate some helpful message pointing to the problem? Even if the messages make no sense to you, they might to someone at DreamSourceLab.
You might have to spend some time getting drivers for the device installed to get the most informative messages. I have no idea what's involved in installing software for the U3P100 on Linux, but Linux is officially supported.