Every hour HardwareGrowler reports this almost identical sequence of events, as seen in this summary from 3.30am this morning until midday: Volume Mounted Today 03.30 Volume 1 Volume Mounted Today 08.00, 09.00, 10.01, 11.00, 12.01 Volume 2 Ethernet deactivated Today 08.10, 09.09, 10.10, 11.09, 12.10 Interface: en0 IP address acquired Today 08.10, 09.10, 10.10, 11.09, 12.10 New primary IP: xxx.xxx.x.xxx (Private) IP address released Today 08.10, 09.09, 10.10, 11.09, 12.10 No IP address now Volume Unmounted Today 08.11, 09.10, 10.11, 11.10, 12.11 Volume 2 Airport connected Today 08.11, 09.11, 10.12, 11.11, 12.12 Joined network SSID: Xxxxx BSSID: xx:xx:xx:xx:xx:xx IP address acquired Today 08.11, 09.11, 10.12, 11.11, 12.12 New primary IP: xxx.xxx.x.xxx (Private) IP address acquired Today 08.11, 09.11, 10.12, 11.11, 12.12 New primary IP: xxx.xxx.x.xxx (Private) Ethernet activated Today 08.13, 09.12, 10.13, 11.12, 12.13 Interface: en0 Media 100baseTX <full-duplex,flow-control> IP address acquired Today 08.13, 09.12, 10.13, 11.12, 12.13 New primary IP: xxx.xxx.x.xxx (Private) Volume Mounted Today 12.38 Recovery HD Volume Unmounted Today 12.38 Recovery HD I have replaced data with possible security issues with the letter 'x', but the IP address is the same every time, as are the SSID and BSSID numbers. As you can see from the indented part, my ethernet modem disconnects at approximately ten minutes past every hour during the daytime, there is a flurry of activity as AirPort tries to reconnect and then the modem reconnects a couple of minutes later. I installed Lion around the same time that this started but I can't be sure whether that has anything to do with it. I have Chronosync schedules running throughout the day which probably explains volume 2 being mounted and dismounted - I guess it is programmed to go to sleep after ten minutes of inactivity. However as far as I'm aware I never have anything scheduled for ten past the hour that could trigger this. Anyone anything like this before that could help solve my mystery?