Mac -=- Removing dot underscore "._" files...

In some cases involving the Apple Double format, moving a file to a different file system will cause the prefix "._" to appear on a file name. The files "._" are invisible when you're trying to list the file even with "ls -al" but you can see them when you compress a file. 

To remove them, you can go on the root of the directory and type

find . -name '._*' -delete

In order to PERMANENTLY resolve this issue, you can however, add one of the following 2 lines of code to your .bash_profile file in your home directory:

# for Tiger OS 10.4 or earlier
export COPY_EXTENDED_ATTRIBUTES_DISABLE=true

# for Leopard OS 10.5 and later
export COPYFILE_DISABLE=true