'Shuffle' issues!!!

Wazzup with this!!! Songs in folders linked to iTunes library, uploaded into iPod Shuffle. Change songs to different folders and thzz it - All songs from iPod are deleted.
Man!! Tht sucks. Once I insert my iPod into USB, all songs are synchronized with the library which ends up in deleting the songs from iPod without my permission. What a crappy design! Atleast a warning? a request to the user!!!
I wish Apple makes this a bit more user friendly...