Does anyone have a solid solution to this issue?
I've exported the posts from a pre-existing WordPress site (via Tools > Export, by selecting the 'Posts' radio button and clicking 'Download Export File').
When I import the XML file into a completely fresh installation of WordPress (ensuring the 'Download and import file attachments' checkbox is ticked) I receive a lot of 'Failed to import author...' messages (which, I assume, happen because the importer has already imported that author) and an 'All done' message.
Posts and comments appear to have been imported correctly but the Media Library is completely empty.
I can manually copy the 'wp-content/uploads' folder from the old site to the new via FTP, but how do I ensure that the Media Library is populated with the correct metadata (e.g. Title, Alternate Text, Caption) and that the galleries are attached to each post?