I think that I found the cause and a solution. http://www.nslu2-linux.org/wiki/FAQ/DealWithAutoSpinDownOnSeagateFreeAgentby jjoshua - Debian
I opened up a new dockstar and seagate freeagent go 320gb drive to use as a file server. I'm running the default pogoplug linux. After partitioning and formatting the drive using ext3, I'm getting intermittent errors like this: [ 2960.470000] sd 0:0:0:0: Device not ready: <6>: Sense Key : 0x2 [ 2960.470000] : ASC=0x4 ASCQ=0x2 [ 2960.480000] end_request: I/O error, devby jjoshua - Debian