We've encountered a strange problem accessing a SharePoint 2010 document archive through Windows Explorer on a Windows 7 machine. The archive has been mapped as a network drive and everything works as expected most of the time. However, some folders can not be accessed. Windows Explorer alternates between giving an error message ("[search path] refers to a location that is unavailable. It could be on a hard drive on this computer, or on a network. ...") or opening the folder, but without any of the content showing. Other folders at the same level, with similar name and similar content, works as expected.
If we go through the web browser, everything works perfectly.
Potential problems we've ruled out include not having a site at the root, forbidden characters in folder or document names, and too long names or paths.
We've looked high and low for a solution, but haven't even found anyone with this problem, let alone a solution. Any ideas?