Just changed the user account name on my Macbook Pro [OSX 10.6.8] yesterday, following these instructions, with no visible problems in the home directory. Today, I noticed that any new application I install is listed as being owned by _unknown, in the permissions section. This can be fixed by adding my current username and giving me ownership, which automatically deletes _unknown from the list. Until I do this, there are errors I encounter with some software, as it is unable to read/write files in ~/library, where the same problem persists. Is there any way I can prevent this from happening in the future? I already repaired a lot of the permissions using BatChmod.