Read this thread on BookIDs.
Hoster 3.108 shows you any duplicate BookIDs you have in your computer, when you run the
Build Songs Database as any duplicates found for an already listed BookID are stored into the SongBookDBLog.txt file, saved in your [installed directory]\Hoster\Databases folder.
There are three ways duplicates can occur:
- Importing on 2 Computers - As Mike has pointed out above, if you are not careful when importing on 2 different computers, each with their own Songs Database holding their used BookIDs, you can import songs with duplicate BookIDs.
- RE-Importing Songs - In the Import screen, if you are importing a disc you have already imported a track from, the Status field shows IMPORTED. If you click the Sel check box beside that track, you will import it again. Now, here's where your duplicates may have come from. In Hoster versions prior to 3.108, if you CHANGED the Save To Folder for what you are now importing so it is different from where you earlier imported the same song, it would create a duplicate file in the currently selected Save To Folder.
We fixed this in Hoster 3.108. When you re-import over an existing file, it AUTOMATICALLY uses the same path/folder to save the new file as was used for the existing file. Thus, it will now replace the prior file, no matter where you save it to before. The Save To Folder current setting is IGNORED.
- Illegal Swapping KMA Files
- This can also generate duplicate BookIDs on your system. This is illegal, and if you are caught you can loose all your equipment, and even your car/van for transporting stolen songs. 
We realize that honest customers can end up with duplicate BookIDs from the first two means above, and need a simple way to fix this.
Hoster 3.2 will automatically renumber any duplicate BookIDs found when running the Build Songs Database command. Each duplicate will be numbered the next lowest available BookID Root with the Track# of the duplicate file appended at the end as is normally done to create the finished BookID.
