I sent email to
webmaster@xnview.com with images of the categories screens showing the categories repeated 3 and four times.
I did some more work on the problem.
The thought occurred to me that the code may be repeating the categories when I open it because it thinks it needs to rebuild the categories data base. Something might be triggering that code.
I might have deleted the data bases once in the past.
So I decided to uninstall xnview and reinstall it. I thought that might recreate the database once and it might work from then forward.
This would eliminate anything in my .ini files as possible causes.
After several uninstall and install cycles I finally deleted categories.db and xnview.db, all the xnview files, and did what I think was a clean install.
I had to go through several cycles to find the data bases in c:\windows\application data.
When I restarted xnview the first time I saw the categories once.
I also observed that XnView created xnview.db, categories.db, and xnview.ini in c:\application data\xnview directory after I started the program, not during the install.
So there is code on the program, as opposed to the install, that creates the default categories.
I then started xnview a second time and saw the problem again: the categories were repeated twice.
The only unusual things I know of about my installation are Win 98 SE and I have the xnview directory on drive f:\program files\xnview instead of c.
It looks to me like something is erroneously triggering the code that writes the default categories when they already exist in the data bases.