1) I'm confused as to why you removed songs from a library that jrmc can't see. If jrmc couldn't see the files how do you remove them? In any event make sure the file types that you are trying to import are selected on the import options. It is possible they imported them as data so check in the documents file type on the left hand side where you find audio, video, playlists. etc. If you can't see a documents heading then you're fine
2) When you select import a folder you will see 2 option boxes at the bottom. Deselect ignore previously removed from library