Indexing

[stublack]

I have an indexing problem. When I add new karaoke videos to a particular folder it keeps track and hides all the indexed tracks. I think that file has become corrupted somehow so now when I add new songs to this folder it only indexes and hides the tracks that I just added in the last few weeks and shows all the other over 4 thousand tracks that have been indexed previously over the last years. There is no problem with the songs being on the database and finding them in the search. It just a lot longer to index new songs because even though you have the hide indexed tracks ticked it show those older songs and you have to scroll through them each time.
I know I can delete all these tracks and reenter them that would take a long time. Can I just re-index them without a delete? Will this cause duplicates. I hope this is not too confusing