A customer today had the problem that he could not connect to the Quickr server via the MS Office connectors. He got an error 12029 from all Office products while the Explorer and Notes connectors just worked fine.
In this special case the local firewall on the client caused that issue. The firewall blocked all network connections from the Office suite. After allowing Office to establish a network connection everything worked fine again. So if you have connectivity problems don't forget to check the firewall settings on the client.