ma_t14, Yes, I have read that wiki.
The act of importing, per se, isn't the issue, so much as having to tell mb to scan any newly added subfolder, before it will see that subfolder. there is a dialog of checkboxes that indicate which folders to scan. but each newly added subfolder needs to be checked manually. Simply checking the main folder isn't sufficient.
and then, after the folder has been scanned. there are more filters to deal with, otherwise mb won't display the newly added folder along with the other folders. Again it has to checked as part of the "filter". Without using filter, any and all folders on the drive will also show up in mb.
Hope this helps.