Currently having trouble syncing iPod from iTunes... Need help!

My iPod classic which is roughly a year old... has been experiencing some difficulty. My iPod can sync about 400 songs and then, all a sudden, iTunes starts freezing and won't close or practically do anything. So then i have to restart my computer just to get some activity from my computer. Error messages of all sorts start to appear when it gets to 400 to 500 range. Some are unknown and some are (-69). Anyone have any information to help, please. If not, my 250 dollar investment is equivalent to a rock.

Added:

**Also when i try to eject after doing 350 or so songs it deletes the whole ipod...*

iPod classic, Windows 7