In both LR 4 and LR5 when the import directory is the same as the destination directory a duplicate file with a xxxxx-2.xxx is created in the hard drive folder when a new file is imported into the catalog. We tried recreating the profile, creating new catalogs and choosing different options and ran many tests. We were not able to determine the cause. This happens in both LR4 and LR5. I usually shoot in NEF and convert to DNG. So this problem never occurred until I tried adding some older jpg files to my catalog. It also occurs when I try and add a DNG file converted by a previous catalog.