Purchased music won't sync to iPod

[WolfStock]

Hi,

I purchased some music recently, and for some reason it won't sync to the iPod. I can download other music from CD no problem. Also I can play the music I purchased recently on the PC no problem. But for some reason iTunes just doesn't sync that album to the iPod. I don't see any way to explicitly send music to the iPod - all I know how to do is just insert the iPod into its base to sync the music. Is there any other way? I tried drag-and-drop, but that doesn't work, even for non-purchased music.

Any ideas? Thanks.