I’m on Windows 8.1 Pro 64bit.
The 3D Warehouse opens from within SU, but is slow. When I try to download a model, it sits there for a while and then I get a message saying that the connection has timed out. That is, the Download Progress dialog comes up but never gets off 0%, and the I get the message “An error occurred when connecting to the 3D Warehouse. The operation timed out.”