PeterW, I would contact Pogoplug support to have them check this out.

Peter Redmer
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I contacted Pogoplug support about the same issue. Technician AdamC's response was disable your antivirus and firewall protection (in my case McAfee). That's an unacceptable way to operate and an unacceptable answer. I hope Pogoplug resolves this issue quickly, otherwise this product will be useless to Win 7 users.

I know some others in the forums have been having problems as well so, in case it helps, here's at least what I discovered about my problem:

I went to my network and sharing center.
Within this window, my current network connection established, I glanced down about half way (below the "view active networks" section) at the "Change your network settings" section.
The third clickable hypertext option is "Choose Homegroup and Sharing Options" so I clicked it. (It's below "Connect to a network" and above "Trouble shoot problems.")
The second section down on the window that comes up is "Share Media With Devices."
"Stream my pictures, music, and videos to all devices on my network" was unchecked, so I clicked its checkbox.
To be safe I also clicked all the unchecked checkboxes in the "Sharing Libraries and Printers section above, but I think the aforementioned "Stream pictures..." checkbox below it was what probably did the trick.

In retrospect, kind of a simple oversight on my part, so maybe everyone's already way ahead of me on this one, lol. But for whoever it helps, there ya go. ;)