Why on earth does my iPod classic take so long to sync?

its one of the new 120GB ones and it takes FOREVER to sync in iTunes, while its conected it also slows down all of iTunes functions. it doesn’t occur to my other iPods (an iPhone, a Shuffle, a Nano) huh? any help? i’m running it on an imac G5 (pre intel) and it works fine as my desktop for most other things but since i’ve upgraded to a new macbook i mainly run it to store my music and photos and to email and surf from. its been fine for years, especially with iPods