Itunes wont sync my library

I don't get it... I have over 2800 songs on Itunes, on random days it will sync 99% of the songs, other days i lose all my songs and get less than 50% on there and i get an error of "Ipod can not be found (error -54)" when my Ipod is PLUGGED IN TO THE USB!! I am so over this, this has been going on since I upgraded itunes past Itunes 10.

My Ipod and Itunes are all at the latest updates. I would simply get rid of Itunes and reinstall it, but i have like 13 playlists and can't afford to lose those.

Any ideas?