I posted the following in the Macpro forum by mistake; I have a mid-2010 27" imac with an external Seagate firewire drive. I always had this issue on 10.8 and older versions of OS X. Along came 10.9 and then 10.9.1 and things worked as advertised until 3 days ago. For the last three days every time I wake the iMac up I have to unplug/replug the Seagate. The drive connects using AFP. Someone must have an idea what is causing this issue. I've searched in several places across the 'net and it does't seem to be hardware related. Since I posted that it started to work again but then today the problem returned. Other than Safari and/or Chrome and Mail I haven' been doing anything that might explain it. Does anyone have any ideas???