Weird Dialog Box When Copying Files

I just setup my first ReadyNAS and started copying music and photo files today.  The files are currently on a Windows Home Server machine I built in 2009.  I moved them to the respective "Music" and "Pictures" folders on the NAS by doing a copy and paste function.

For every single file that I transferred, I got a dialog box message asking me "if I was sure that I wanted to copy the file without properties" or something like that.  I had to click yes to actually transfer the file.  Once in the new folders, the music and photos seem to be fine.  I even have a lot of album art jpg files transferred with the music.  All of those files are marked as "hidden" and "read only" under properties when I checked them on the NAS.  I had those same "properties" checked on the Windows Home Server.

Does anyone understand why I'm getting that dialog box question for every file and what it actually means?  What "properties" are not being transferred to the NAS?  The properties of a file that are available by right clicking a file seem to transfer fine.

Thanks!