Hi Folks, CentOS 5.5 x86_64 Asrock-Board with 2 USB3 plugs. Normally USB3-drive is detected. But occasionaly after "umount" next time this drive or other ones will not be detected. I have to boot the PC - than it works - till next unrecognition. On USB2 plugs all works correct. No messages in /var/log/messages nor dmesg. What happens here? Board failure - or other reasons? Some hints welcome. Timothy