[ovirt-users] USB redirect

Hello everybody, I have an oVirt 3.4 deployment and I have some Windows 7 Enterprise 32 bits guests. I can't redirect USB from a Windows 7 client. I'm using remote - viewer as console. Also I have observed something wrong in my administration portal. The oVirt documentation says that I have to select Native USB mode in console properties in VM configuration but after select this mode, it doesn't remain. If I check this value in console configuration again I can see disabled, native mode value have been changed. Is there someone have had this problem?, and how I can solve it?, is it necessary to install in Windows clients us clerk software? Many thanks in advanced. Juanjo.