When you try to import the existing albums, it should be connecting to uagrugby.com, and not to pyroshugo.jalbum.net. You don't have a jAlbum hosting account - your albums are hosted on your own web host.

Look at Tools > Upload/Manage. There should be an uploading profile for uagrugby.com. If you see one for pyroshugo.jalbum.net, remove it.

You do understand that when you import a published album, that will not include your original, full-sized images. It will include only the slide images, the ones that have been scaled down to 1024px. The full-sized images aren't on the web site, so importing can't get them.