If two file names have the same name a number is added by antps script. I have added alot of thumbs named title1.jpg but they are changed to title1.2.jpg title1.3.jpg etc:

http://pics.imcdb.org/1987/title1.jpg
http://pics.imcdb.org/1987/title1.35.jpg
http://pics.imcdb.org/1987/title1.47.jpg