When I copy files from my Win 7 Home to other computer with Win 7 Pro (push, I open my Win Pro machine from my Home, and drag&drop files to its shared folder), it regularly hangs on "cannot reach destination location". However, if I click "Try Again" on the copy process, it resumes immediately most of the time. Sometimes, it fails again, and then waiting for a while (2-3 minutes) and clicking Try Again works. And sometimes some files just will fail all the time, but when I click "Ignore", it resumes copying other files just fine. At any point in the failure, I'm able to access the folder through Explorer (Network->My other pc->destination folder) with no problems, but the Try Again will fail anyway. The specific behavior is kind of random.
What are the possible causes and how to diagnose them? Network traffic seems to be fine ( = not a WiFi problem, I'd guess?)