I can open it in Computer and open the files that did copy (about half the folder). I copied a bunch of photos from my son's wedding with no problem, then when I tried to copier a slightly larger folder across (635 MB) I get the same message 'The item is no longer in this location'. Today the Freecom has started to do the same. So I kind of gave up and planned to return it under warranty and rely on the old Freecom box in the meantime - just cutting back on the number of files backed up. Cut a long story short - including reformatting the Seagate several times - we fiddled around until it worked fine on my son in laws system Windows 7 32 bit Home - brought it back and it worked fine on mine for a few minutes - then began the same behaviour again.
A week or so before Christmas the Seagate kept 'disappearing' it would be visible in Computer Management where it appeared to be 'running normally' but when i tried to access the drive I would get messages saying the item was 'no longer in that location'.
I have two external drives - a relatively old 150Gb freecom and a 6 month old 1Tb Seagate - both of which worked fine with old Vista Home setup.
My Windows 7 professional 64 bit system has caused several issues for me which may be related.