I have a Windows XP VM on a ESXI host. A USB license dongle is passed through to the XP VM. The application fails to detect the license dongle after a certain period of time, but the dongle still shows up in Device Manager. It can only be fixed by restarting the VM. This is only a problem in the VM. We have a physical XP machine using the same software with the same license dongle but it doesn't have any issues.