I'm a happy owner and user of the Fujitsu ScanSnap iX500 which I use on a Windows VM to leverage the software it came with mainly for OCR. The scanner works flawless when simply scanning documents and pictures. Once a carrier sheet is introduced though, it fails to scan every time! I'm wondering if I have a flaky piece of hardware that I need to invoke the warranty on or if there is a possibility data is not being passed from the ScanSnap to the VM. The only thing I can think of is if the ScanSnap is trying to pass data over a newly spawned USB device that isn't open for communication. Is there any way to identify devices that come and go in VMWare logs?
Note: I opened up a ticket with Fujitsu over a month ago and the resolution was they sent me another new carrier sheet which has proven to fail as consistently as the original one that shipped with the unit. I'm trying to verify that VMWare is not the cause before I invoke the recommended unit replacement in another ticket. I'm not sure that the software that comes with the ScanSnap can be installed on another computer without violating the TOS, but I have a laptop that just became available that I can test with if I get permission first 
Specs:
HOST:
Ubuntu Studio 14.04 64 bit
3.13.0-17-lowlatency (used patch to compile for 3.13 kernel on install)
VMWare Workstation 10.0.1 build-1379776
RAM 12032 MB
Guest:
Windows 7 Professional SP 1 64 bit
VMWare Tools for Windows installed: 9.6.1, build-1378637
VMWare Settings:
USB Compatibility USB 2.0
Enabled: Automatically connect new USB Devices
Disabled: Show all USB input devices