sansa clip plus and itunes - how to transfer files

I have found if you drag the icon to the desktop you can see whether it is an .m4a or a .mp3 extention.  I have found that it works fine, however, I am running into another problem. For each song I transfer, I am getting a junk file that has a period (.) and an underscore (_).  These junk files are just there, they don’t play, but they do affect the counter telling me how many songs I have.

I was wondering if you see these junk files show up.  For example the song Imagine would look like this:  ._imagine

Very annoying. 

Thanks,

Jimmy