repeating console errors with USB plugged in

[bjlockie]

I get these errors repeated to the console if I boot with a USB device plugged in.
What does this mean:

scsi_id[5542]: scsi_id: unable to access '/block/sde'
udevd-event[5574]: wait_for_sysfs: waiting for '/sys/devices/pci0000:00/0000:00:
02.1/usb1/1-6/1-6:1.0/host28/target28:0:0/28:0:0:0/bus' failed
udevd-event[5574]: wait_for_sysfs: waiting for '/sys/devices/pci0000:00/0000:00:
02.1/usb1/1-6/1-6:1.0/host28/target28:0:0/28:0:0:0/ioerr_cnt' failed