Can't connect to Windows Home Server folders

From home folder/browse network I can see both the other two (non-Ubuntu) PCs running on my network, my main PC and my WHS machine. When I click on the icon for my main PC, as expected it asks for a username and password. However, when I click on my WHS machine icon, it shows me the list of folders, and then when I click on any of them rather than prompting me for a username and password, it just says "Unable to mount location: Failed to mount Windows share."

This is very frustrating for a mostly novice user (trying 12.04).

Any help appreciated. I've seearch already quite a bit but found no solution.

Thanks,
-Chris c.