I am trying to copy files from my Macbook's hard disk to my NAS. The latter is a ReadyNAS Duo and is mounted as an AFP volume. The files are about 5MB each and I copy them by selecting in a Finder window all the files that I need and then dropping them onto the destination directory. Almost always some of the files do not get copied to the NAS. For example, if I select 200 files and then start the copying, everything looks at the beginning normal (while the copying takes place the Finder window for the destination directory is updated to show 200 files while it was empty before), but after the copying ends the destination directory shows less than 200 files (let's say 190). If I copy again the same 200 files to the NAS, without replacing already copied files, the remaining 10 files are usually copied correctly. In a few cases, I have to repeat the process a third time. Notice that the Finder does not give any warning that some of the files have not been copied at any stage. I am wondering if this a known problem with AFP and the Finder and/or if there is something that I can do to solve this problem.