iPod technical question...

[arib]

So, since getting my iPod, I've been using the manual option to manage my ipod's content. (Not having enough HD space to store all of my music on my computer).

Now that I've discovered podcasting I've been updating my iPod's contents daily, ansd it's getting to be a chore.

If I switch back to automatic updating, will all of the music that's on my iPod, but not on my computer be deleted? How about auto updating of certain playlists?