I have a 160gb ipod classic, when synced with itunes and try to tranfer 8000 songs to it it will tranfer about 5500 (random number of songs) the it will show "unknown error -50 or -63", itunes will freeze and nothing would happen. I've tried different tranfer combinations with no luck. I can tranfer the same songs to my iphone. Any advise would be appreciated, thanks.
Error -50 is a connection timeout, when iTunes is trying to transfer huge number of songs to your iPod, see this support link.
http://support.apple.com/kb/TS1583
I would suggest that you split your songs into several playlist of 1000 songs, and sync 1 playlist at a time.
From all the posts with Sync problems, I think that transfering to iPod Touch or iPhone is no problem for the Apple Mobile Device driver, only it doesn't behave well with iPod Classic, after all, not worth supporting a gadget that is becoming redundant, it will make iPod owners buy the latest Apple products.
Oops sorry, this link is better at explaining your problem.
ipod classic error unknown -50
