No problem. As I recall, there were a lot of options in nPlayer (SMB, UPnP, WebDAV, etc.), but what works for the Media Drive is FTP. So, once your iPad is connected to the Media Drive wifi, go to into nPlayer and select Network at the bottom. From the list, select FTP. At this point, I think maybe you have to enter the URL of the Media Drive(?), or maybe you select "Scan Network"(?). The URL of the Media Drive is 192.168.11.1, and then enter the password. You should be connected at this point, and able to navigate to your folder(s).
If you have any questions, quoting my reply will help get my attention.