Follow these steps:
Locate and then click the following key in the registry:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
On the Edit menu, point to New, and then click DWORD Value.
Type NoSimpleNetIDList, and then press ENTER.
On the Edit menu, click Modify.
Type 1, and then click OK.
Again later ...
Nop, it was no a permanent solution. I had my machine running overnight. Yesterday it worked, this morning not anymore.
It's really weird.