File renaming

I normally rename by photo files in Bridge using "tools".  Yesterday, I renamed 26 files and unlike previously it renamed those 26 files and created duplicates of these files.  So I brought them into camera raw and deleted the duplicates -- camera raw deleted all 52 files.  Luckily, I had these images on the SD card so I was able to reload.  I have used this process for years - why has it changed.  I checked to see if there was an update that I missed -- all was updated.  Help me figure how to rename files without getting duplicates; and if I get the duplicates, how to delete the extra files without losing all the files.