Note: our IT department highly recommends that FTP requests go through the ftp.hp.com URL servers, as opposed to being accessed through a server's IP address, so that the actual server assigned to handle an ftp request is the least busiest. By accessing the ftp server by IP address, it is a "hit-and-miss" chance whether that server will be busy or not.
In regards to the reason SDM might be running on a slow connection, it would be quite difficult to pinpoint the exact cause for this slowness without point-to-point real-time packet monitoring since any node between the server and the client can be the cause of "slowness".
Having that said, if the nodes are not the cause for this slowdown, then it is logical to assume that SDM is pegging a server that is either being maintained or is experiencing a higher-than-usual workload. In most cases, closing SDM and launching it again in a few minutes should do the trick.